Yook Sung-jae: The Life Story Behind BTOB's Star

Yook Sung-jae is the singer and actor who makes people smile, and then makes them cry. He debuted as the youngest member of the boy group BTOB in 2012, when he was seventeen years old, and he became known for his bright voice, his humour, and his warm heart. In Goblin he played a young man caught between a goblin and a grim reaper, and viewers loved his funny, loyal character. In The Golden Spoon he played a poor boy who swaps lives with a rich boy, and in The Haunted Palace he played a man fighting spirits in a royal palace. His story is about growing up in public, from a cheerful teenager to a serious leading man.

He was born in Yongin on 2 May 1995, and he was discovered as a teenager and trained for years before his debut. He spent his youth in practice rooms, learning to sing, dance and perform, and he learned the discipline that would carry him through every change that followed. He is known for his honesty, his humour, and his kindness to his fans.

This is the story of a young man who grew up on stage and on screen, and who never lost his warmth. Yook Sung-jae shows that a cheerful heart and hard work can carry a person from a boy group to a leading role, and that growing up does not mean losing your joy.

A Yongin Boy With a Bright Voice

Yook Sung-jae was born in Yongin on 2 May 1995, a city south of Seoul known for its parks, its schools and its family life. He grew up in ordinary family life, going to school and living the normal life of a Korean boy. He was the youngest in his family, and he was known for his bright smile and his lively manner. He loved to sing, and he sang whenever he could, at home, at school, and with friends.

As a boy he was drawn to music, and he began to dream of becoming a singer. He liked the idea of standing on a stage and making people happy with his voice. He did not have a famous family or connections in the industry. He had only his voice, his smile, and his willingness to work hard. That was enough to start, and he began to look for a chance to train.

He was discovered as a teenager and invited to become a trainee at a music company. Trainee life is hard for a young person. He left home, lived in a dorm with other trainees, practised singing and dancing for many hours each day, and waited for a debut that might never come. He accepted that life with a cheerful heart, and he learned discipline, teamwork and patience before he was eighteen.

His family supported him, and that support mattered. He knew that his parents believed in him, and that belief gave him strength when training was hard. He practised every day, he learned from his teachers, and he waited for his moment. When it came, he was ready, and he took it with the same bright smile he had as a boy in Yongin.

BTOB and the Youngest Member

Yook Sung-jae debuted in 2012 as a member of BTOB, a seven-member boy group, and he was the youngest member, known as the maknae. He was seventeen years old, and he was the lead vocalist, known for his clear, bright voice. BTOB debuted with a strong, energetic image, and they gained fans who loved their music, their harmony, and their humour. He quickly became a favourite, because of his smile, his jokes, and his honest way of speaking.

BTOB worked hard for years, releasing music, performing on stage, and building a loyal fan base. They were known for their vocal talent, and for their warm, funny personalities. Yook Sung-jae was a central part of that image. He made people laugh in variety shows, he sang with feeling in ballads, and he treated his fans with warmth. He became known as a cheerful and kind idol, and that reputation has stayed with him.

Life in a boy group is hard. Members live together, practise together, and share both success and failure. He learned how to be a good group member, how to support his older members, and how to put the group first. He also learned how to handle fame as a teenager, with cameras, fans and pressure everywhere. He handled it with humour and honesty, and fans loved him for it.

Through BTOB he also learned about music in a deep way. He sang ballads, dance songs, and emotional songs, and he learned to use his voice to tell a story. That musical training later helped his acting, because acting, like singing, needs feeling, timing, and truth. He was building skills that would serve him in two careers at once.

Who Are You: School 2015 and a First Acting Step

While he was still active in BTOB, Yook Sung-jae began to try acting. He made his acting debut in the drama Who Are You: School 2015, playing a young man in a school story about love, friendship and bullying. The role was a good first step, because it used his youthful image and his natural warmth. Viewers noticed his acting, and they liked his honest, unforced style.

He learned acting on the job, watching older actors and taking lessons. Acting was different from singing. A singer performs a song in a few minutes. An actor lives a character for weeks, learning lines, understanding feelings, and working with a team. He took that challenge seriously, and he worked hard to improve. He knew that people would judge him as an idol who wanted to act, and he wanted to prove that he was a real actor.

His early acting roles were in youth dramas, where he played students, friends, and young men in love. Each role taught him something new, and he grew with each one. He learned how to play comedy, how to play sadness, and how to work with a camera. He was still a singer first, but he was becoming an actor as well, and that double life would shape his whole career.

He also appeared in variety shows, where his humour and honesty made him a favourite. He was known for saying what he thought, for laughing easily, and for treating people with kindness. That variety work made him known to viewers who had never heard his music, and it brought him new fans. He was becoming a star in more than one world.

Goblin and the Role That Made Him a Star Actor

In 2016 and 2017 Yook Sung-jae took on the role that changed his acting career, playing Yoo Deok-hwa in Goblin, one of the most loved Korean dramas of all time. Goblin told the story of a goblin who needs a human bride to end his immortal life, and a grim reaper who lives with him. Yook Sung-jae played the young, rich and funny grandson of the goblin’s family, a character who brings humour and warmth to a dark and magical story.

His character, Deok-hwa, was loved by viewers for his humour, his loyalty, and his surprising depth. He made people laugh in almost every scene, but he also showed a serious side when the story turned dark. In the later episodes, his character held a great secret, and Yook Sung-jae played that secret with care. Viewers were shocked and moved by the change, and they praised him for making a comic character feel deep and real.

Goblin was a huge hit, watched by millions in Korea and around the world, and it made him a star actor. He was no longer only the youngest member of BTOB. He was an actor who had played a memorable role in a classic drama, and his name was now known to drama fans everywhere. It was a turning point, because it proved that his acting was not a side project. It was a real talent.

After Goblin, he received many more acting offers, and he chose them with care. He wanted roles that would help him grow, not only roles that would repeat his success. He had learned from his music career that a fast rise needs steady work to last, and he applied that lesson to acting as well.

Mystic Pop-up Bar and The Golden Spoon

In 2020 Yook Sung-jae starred in Mystic Pop-up Bar, a fantasy drama about a bar that appears at night to help people solve their troubles. He played Han Kang-bae, a young man with a strange gift: people tell him their secrets when they touch him. The drama was warm, funny and sad, and his performance showed a new depth. He played a lonely young man who learns to help others, and viewers loved his journey.

The role was a good test, because it asked him to be funny and sad at the same time. He played a man who is tired of his gift, but who uses it to heal others. That idea, of a painful gift becoming a way to help, is close to his own life as a singer and actor, where his talent brings both joy and pressure. He played it with honesty, and the drama was praised for its heart.

In 2022 he starred in The Golden Spoon, a drama about a poor boy who uses a magic golden spoon to swap lives with a rich boy. He played Lee Seung-cheon, a young man who wants a better life for his family and who learns the cost of wishing for wealth. The drama was a hit, and his performance was praised for its seriousness and its feeling. He played a young man caught between two worlds, poor and rich, and he made that struggle feel real.

These two dramas showed his growth as a leading man. He was no longer the funny supporting actor from Goblin. He was a star who could carry a whole drama, and who could play complex, serious roles. He had grown up on screen, and his fans had grown up with him.

Military Service and a Quiet Pause

In 2020 Yook Sung-jae began his military service, a duty for all Korean men. He enlisted in May 2020 and served his time away from the stage and the screen. For a star at the height of his fame, two years away is a serious pause, but he accepted it as part of life. He had already learned, in his music career, that pauses can lead to new beginnings, and he faced his service with the same calm he had always shown.

His service was a time of growing up, of living a disciplined life far from fame. He worked with many kinds of people, learned new skills, and lived without the pressure of cameras. That experience gave his acting a new depth, and it made him a more mature man. He was discharged in November 2021, and he returned to a world that had kept moving, with new stars and new dramas.

Fans waited for him with patience, because they knew his history. He had waited before, as a trainee, and he had returned stronger. They believed he would do the same after the army. His return was quiet and steady, without noise or complaint, and he began choosing new roles to show his growth as an actor and as a man.

His time in the army also taught him about responsibility. He had lived a life where he was responsible for others, and he had learned the value of discipline and teamwork in a new way. That experience will shape the roles he takes next, and it will give his work a new seriousness that his early roles did not have.

The Haunted Palace and a Leading Man Returns

In 2025 Yook Sung-jae starred in The Haunted Palace, a fantasy historical drama about a man who fights evil spirits in a royal palace. He played a leading role in a story full of magic, action and romance, and his performance was praised for its energy and its depth. The drama was a success, and it showed that he had returned from military service stronger and more skilled than before.

The role was a good test for his return, because it demanded action, fantasy and romance all at once. He trained hard for the action scenes, and he played his character with a new maturity. Viewers saw a young man who had grown up, who had served his country, and who had come back ready to lead a major drama. It was a powerful return, and it won him new fans.

He has also continued his music career with BTOB, releasing songs and performing for his fans. He has kept both careers alive, music and acting, and he uses each one to help the other. His singing gives his acting feeling, and his acting gives his singing stories. That balance is rare, and it is why he is loved in both worlds.

Today Yook Sung-jae is a leading man with a long future ahead of him. He has grown from a cheerful teenager in a boy group to a serious actor who can carry a historical fantasy. He has done it by working hard, by staying humble, and by keeping his warmth. His story is still being written, and his best work may still be ahead of him.

Humour as a Way of Acting

Yook Sung-jae is known for his humour, and humour is a serious part of his acting. He makes people laugh in variety shows, in dramas, and in interviews, and that laughter is not an accident. It comes from a person who sees the funny side of life, even when life is hard, and who uses laughter to bring people together. In acting, humour is a powerful tool, because it makes a character feel human. A character who never laughs feels like a picture. A character who laughs feels like a person, and he knows how to make that laughter feel real.

His humour in Goblin is a good example. He played a young man who is funny, rich, and a little foolish, and his jokes made the audience laugh in almost every scene. But his humour was not only for laughs. It hid a deeper truth, because his character carried a great secret, and the jokes were a way of hiding that secret. When the secret was revealed, the audience understood why he had joked so much. His humour was a mask, and a good mask tells you something about the person behind it.

He also uses humour to handle pressure. Life as an idol and an actor is full of pressure, with cameras, fans, and long hours. He deals with that pressure by laughing, by joking with his fellow members, and by keeping a light heart. That lightness is not foolishness. It is a way of staying sane in a hard world, and it helps the people around him stay sane too. A set with laughter is a better set, and he brings that laughter wherever he goes.

Humour also helps him play serious roles. In The Golden Spoon, he played a poor boy who wants a better life, a serious and sad story, but he still found moments of humour in it. A poor boy can still laugh, and that laughter makes his sadness feel more real, because it shows that he is still alive, still hoping, and still human. He understands that humour and sadness live side by side, and he plays both at once, which is why his performances feel so alive.

He learned humour from his life in BTOB, where seven young men lived together, joked together, and supported each other. In a group, humour is how you survive long days, how you comfort a tired member, and how you keep the team together. He carried that group humour into his acting, and it made his characters feel like real members of a team, not lonely stars. He plays characters who belong to a group, and that belonging is a large part of his charm.

Finally, his humour is a form of kindness. He makes people laugh because he wants them to feel happy, not because he wants to show off. That kindness is why fans love him, and why his fellow actors enjoy working with him. A funny person who is also kind is a rare gift, and he is that gift. His humour is not a trick. It is a way of loving people, and it shows in every role he plays.

From Maknae to Leading Man

Yook Sung-jae began as the maknae, the youngest member of BTOB, and he grew into a leading man, and that journey is the heart of his story. A maknae is expected to be cute, cheerful, and a little foolish, and he played that role well. He made people laugh, he sang with a bright voice, and he brought joy to the group. But a maknae must also grow up, and growing up in public is hard, because the audience remembers the cute boy and may not accept the serious man. He grew up anyway, and he did it with grace.

His growth can be seen in his acting. In his early roles, he played students and young men in love, and his humour was the main gift. In Goblin, he was still funny, but he also showed depth, hiding a great secret behind his jokes. In The Golden Spoon, he played a poor boy with a serious wish, and his humour became quieter, more thoughtful. In The Haunted Palace, he played a leading man fighting spirits, and his humour became a tool for courage, not only for laughs. Each role shows a new stage in his growth, from boy to man.

Growing up also meant taking responsibility. As the youngest, he once relied on his older members. As a leading man, others rely on him. He learned to carry a drama, to make decisions on set, and to take care of his fellow actors. That responsibility is a large part of what makes a leading man, and he learned it step by step, through his music career, his acting career, and his military service. He did not become a leader in one night. He became one by working, by learning, and by growing up in front of everyone.

Military service was a major step in that growth. He left as a young star and returned as a man, with new discipline and new seriousness. He had lived a life away from fame, worked with many kinds of people, and learned about responsibility in a new way. That experience gave his acting a new depth, and it made his return to leading roles feel earned, not given. He had grown up, and the audience could see it in his face and in his work.

He also grew by keeping his warmth. Many young stars lose their joy when they grow up, becoming serious and cold. He did not. He kept his smile, his humour, and his kindness, even as he took on serious roles. That balance, serious and warm at once, is rare, and it is why his fans have stayed with him from his teens to his thirties. They grew up with him, and they love the man he has become, because he is still the boy they loved, only stronger and wiser.

Finally, his journey from maknae to leading man is a lesson for any young person. Growing up does not mean losing yourself. It means keeping the best parts of your youth, your joy, your humour, your kindness, and adding new strengths to them: responsibility, discipline, and depth. He did that, and his story shows that growing up can be a beautiful thing, if you do it with honesty and with heart.

My Take:

I think Yook Sung-jae’s story is about growing up in public and keeping your joy, and that is a hard thing to do. He became famous as a teenager, and he grew up in front of cameras, fans, and critics. Many young stars lose their joy when they grow up in public. They become tired, bitter, or proud. He did not. He kept his smile, his humour, and his kindness, even as he took on serious roles. I admire that. It tells me that growing up does not have to mean losing your joy. You can become serious and still be warm.

What I love most is his role in Goblin. He played a funny, loyal young man who hides a deep secret, and he made people laugh and then made them cry. I think that is a true picture of many young people. They are funny on the outside, but they carry a serious weight inside. His performance honours that hidden depth, and it makes me want to look deeper when someone is always joking. Behind the joke, there may be a real feeling that needs to be heard.

His time as the youngest member of BTOB also teaches me something. Being the youngest means you must listen, learn, and support your older members. He did that with a cheerful heart, and he became a favourite because of it. I think that is a good lesson for anyone who is new or young in a group. You do not need to shout to be valued. You can listen, learn, and help, and people will love you for it. That is a quiet kind of leadership, and it is very strong.

I am moved by his role in The Golden Spoon, where he played a poor boy who swaps lives with a rich boy and learns the cost of wealth. I think many people dream of being rich, and they think money will solve all their problems. His drama says the opposite. Wealth brings new problems, and it can cost you your family, your love, and your peace. I find that message wise. It makes me grateful for what I have, and it makes me think twice before wishing for a different life.

There is a sad side to his story too. He left home as a teenager, he lived the pressure of fame, and he had to pause his career for military service. Each of those things is hard, and I feel the weight of them. But his story does not end in sadness. It ends in a strong return, in leading roles, and in respect. That gives me hope that hard pauses are not endings. They are times to grow, and you can return stronger if you use them well.

I think about his humour in variety shows. He is known for saying what he thinks, for laughing easily, and for being honest. In a world where many stars hide behind a perfect image, his honesty feels fresh. I want to be honest like that, to say what I think with kindness, and to laugh easily. Honesty does not have to be harsh. It can be warm, funny, and kind, and his example shows that.

His military service also stays with me. He was at the height of fame, and he still went to serve like any other young man. He did not seek special treatment. That sense of duty is rare and valuable. It tells me that fame does not free you from responsibility, and that a real person does what he must do, even when it costs him. I want to live with that kind of responsibility in my own life.

I admire his balance between music and acting. He did not let one career kill the other. He kept singing with BTOB while he acted, and he kept acting while he sang. That balance takes discipline, and it shows that a person can love two things at once. I think many of us feel we must choose one path and give up the other. His life says we can keep both, if we work hard and manage our time with care.

Finally, I think his story is about warmth. He is known for his warm heart, his bright smile, and his kindness to fans. In a cold world, warmth is a strength. It brings people together, it heals sadness, and it makes hard work feel lighter. I will remember his story when I feel cold or tired, and I will try to keep my own warmth alive, to smile, to laugh, and to be kind, even when life is hard. That warmth, kept alive through growing up, is what I will remember most about Yook Sung-jae.

I think about his humour, and I realise how much laughter matters. I often take life too seriously, and I forget to laugh. His example says that laughter is not a waste of time. It is a way of surviving, of staying sane, and of bringing people together. I want to laugh more, to joke with the people around me, and to use humour to lighten hard days, instead of carrying every burden in silence.

I also think about his role in Goblin, where humour hid a deep secret. I think many people hide their pain behind jokes, and we laugh without seeing the pain. His performance reminds me to look deeper when someone is always joking, and to ask how they really feel. Behind the joke, there may be a real feeling that needs to be heard, and I want to be the kind of person who listens for it.

I am moved by his role in The Golden Spoon, where a poor boy learns the cost of wealth. I think many people dream of being rich, and they think money will solve all their problems. His drama says the opposite. Wealth brings new problems, and it can cost you your family, your love, and your peace. I find that message wise, and it makes me grateful for what I have, instead of wishing for a different life.

Another thought stays with me. He left home as a teenager, he lived the pressure of fame, and he had to pause his career for military service. Each of those things is hard, and I feel the weight of them. But his story does not end in sadness. It ends in a strong return, in leading roles, and in respect. That gives me hope that hard pauses are not endings. They are times to grow, and you can return stronger if you use them well.

I think about his military service, too. He was at the height of fame, and he still went to serve like any other young man. That sense of duty is rare and valuable. It tells me that fame does not free you from responsibility, and that a real person does what he must do, even when it costs him. I want to live with that kind of responsibility in my own life.

Finally, I think his story is about warmth. He is known for his warm heart, his bright smile, and his kindness to fans. In a cold world, warmth is a strength. It brings people together, it heals sadness, and it makes hard work feel lighter. I will remember his story when I feel cold or tired, and I will try to keep my own warmth alive, to smile, to laugh, and to be kind, even when life is hard. That, more than any single role, is what his story leaves with me.

I think about his journey from maknae to leading man, and I realise growing up does not mean losing yourself. He kept his joy, his humour, and his kindness, and he added responsibility and depth. I want to grow like that, to keep the best parts of who I was, and to add new strengths, instead of throwing away my youth to become serious.

I also think about his humour hiding a secret in Goblin. Many people hide pain behind jokes, and we laugh without seeing the pain. His performance reminds me to look deeper, to ask how someone really feels, instead of only laughing at their joke.

His military service also stays with me. He left as a young star and returned as a man, with new discipline. I think pauses can make us stronger, if we use them well. I want to use my own pauses to learn and to grow, instead of only waiting for them to end.

I think about his balance, serious and warm at once, and I admire it. Many people become cold when they become serious. He stayed warm, and that warmth is why people love him. I want to stay warm too, even when life asks me to be serious, and to let kindness be part of my strength.

Finally, I think his story is about growing up in public and keeping your heart. He grew up in front of cameras, fans, and critics, and he never lost his warmth. I will remember that when I feel pressured to change who I am, and I will try to grow without losing the best parts of myself. That, I believe, is the true lesson of Yook Sung-jae.

I think about his humour, and how laughter can be a way of surviving hard days. He laughs, he jokes, and he brings light to the people around him. I want to laugh more, to use humour to lighten my own hard days, and to bring a little light to the people I work with, instead of carrying every burden in silence.

I also think about growing up in public, from a cheerful maknae to a serious leading man. He kept his joy while he grew, and that balance is rare. I want to grow in the same way, to add responsibility and depth without losing the joy and warmth that made me who I am.

I keep thinking about his military service, and how a pause can make a person stronger. He left as a young star and returned as a man, with new discipline. I want to use my own pauses to learn and to grow, instead of only waiting for them to end.

I think about his role in The Golden Spoon, and how it teaches that wealth is not the answer to every problem. Money brings new problems, and it can cost you family and peace. I want to be grateful for what I have, and to think twice before wishing for a different life.

I also think about his kindness to his fellow members in BTOB, and how he supported his older members as the youngest. Listening, learning, and helping are quiet forms of leadership, and they are very strong. I want to lead in that quiet way, by helping others shine instead of only trying to shine myself.

I think about his humour, and how laughter can carry a person through hard days. He laughs, he jokes, and he brings light to the people around him. I want to laugh more, and to use humour to lighten my own hard days instead of carrying every burden in silence.

I also think about his growth from maknae to leading man, keeping his joy while adding responsibility. Growing up does not mean losing yourself, and I want to grow in that same way, keeping the best parts of who I was while adding new strengths.

Frequently Asked Questions

How did Yook Sung-jae become famous?

Yook Sung-jae debuted as the youngest member of the boy group BTOB in 2012, when he was seventeen years old. He became known for his bright voice and cheerful manner. He later became famous as an actor through his role as Yoo Deok-hwa in Goblin, one of the most loved Korean dramas of all time.

Who did Yook Sung-jae play in Goblin?

In Goblin from 2016 and 2017 he played Yoo Deok-hwa, the young, rich and funny grandson of the goblin’s family. His character brings humour and warmth to a dark and magical story, and he holds a great secret in the later episodes. Viewers loved his performance, and it made him a star actor.

What is The Golden Spoon about?

The Golden Spoon from 2022 is about a poor boy who uses a magic golden spoon to swap lives with a rich boy. Yook Sung-jae played Lee Seung-cheon, the poor boy who wants a better life for his family and learns the cost of wishing for wealth. The drama was a hit, and his serious performance was widely praised.

Did Yook Sung-jae serve in the military?

Yes, he enlisted in May 2020 and served his military duty, and he was discharged in November 2021. Like all Korean men, he had to complete service, and he did so at the height of his fame. He returned quietly and began choosing new roles to show his growth as an actor and as a man.

What drama marked Yook Sung-jae’s return after service?

In 2025 he starred in The Haunted Palace, a fantasy historical drama about fighting evil spirits in a royal palace. The role demanded action, fantasy and romance, and his performance was praised for its energy and maturity. It showed that he had returned from service stronger and ready to lead a major drama.

What can young people learn from Yook Sung-jae?

Young people can learn that growing up does not mean losing your joy, and that being the youngest can be a strength if you listen and help. He shows that humour and kindness matter, that wealth is not the answer to every problem, and that a pause for duty can lead to a stronger return. His life teaches warmth, discipline, and balance.