# Yook Sung-jae
**Yook Sung-jae** (육성재; born 1995) is a South Korean singer and actor, best known as the sub-vocalist and youngest member of the boy group BTOB and for lead and supporting roles in Korean television dramas such as *[Who Are You: School 2015](https://www.edgepedia.org/who-are-you-school-2015)*, *Guardian: The Lonely and Great God*, and *The Golden Spoon*.[1](https://www.yes24.com/product/author/167127) • [2](https://www.koreajoongangdaily.com/entertainment/who-is-yook-sungjae/12792151) He was born in Yongin, Gyeonggi Province, South Korea.[3](https://www.imdb.com/name/nm6857340/)
| Key fact | Detail |
|---|---|
| Born | 1995, Yongin, South Korea; height 180 cm[3](https://www.imdb.com/name/nm6857340/) • [4](https://asianwiki.com/Yook_Sung-Jae) |
| Group debut | Debuted with the seven-member boy group BTOB on March 21, 2012, under CUBE Entertainment[5](https://ksnapshot.net/btob-yooksungjae/) |
| Acting breakthrough | Gong Tae-gwang in KBS2's *Who Are You: School 2015* (2015), followed by Yoo Deok-hwa in tvN's *Guardian: The Lonely and Great God* (2016–2017)[2](https://www.koreajoongangdaily.com/entertainment/who-is-yook-sungjae/12792151) • [4](https://asianwiki.com/Yook_Sung-Jae) |
| Solo debut | EP *YOOK O'clock*, released March 2, 2020, with the title track "Come With The Wind"[6](https://www.youtube.com/watch?v=tw63M5Putw4) |
| Military service | Enlisted May 11, 2020; discharged November 14, 2021[4](https://asianwiki.com/Yook_Sung-Jae) |
| Agency change | Left CUBE Entertainment in November 2023 after 11 years and signed with iWill Media in December 2023[7](https://fametown.com/en/celebrity/yook-sung-jae/) • [8](https://www.soompi.com/article/1634203wpp/btobs-yook-sungjae-launches-official-x-twitter-account-after-joining-new-agency) |
| Recent drama lead | Yoon Gab in SBS's *The Haunted Palace* (2025)[4](https://asianwiki.com/Yook_Sung-Jae) |
## BTOB debut and group career
Yook debuted on March 21, 2012 as a member of BTOB, a boy group formed by CUBE Entertainment, where he served as a sub-vocalist and the group's youngest member (maknae).[5](https://ksnapshot.net/btob-yooksungjae/) • [1](https://www.yes24.com/product/author/167127) Within the group's wider activities he has also taken part in the ballad subunit BTOB Blue.[2](https://www.koreajoongangdaily.com/entertainment/who-is-yook-sungjae/12792151)
The project's third part closed in February 2020, and his first solo EP, *YOOK O'clock*, followed on March 2, 2020.[6](https://www.youtube.com/watch?v=tw63M5Putw4) • [9](https://musicbrainz.org/artist/110a38cb-1b92-42c2-93ad-d312fa760801)
## Acting career
Yook began acting in 2013 with supporting roles in tvN's *Monstar* and *Reply 1994*.[2](https://www.koreajoongangdaily.com/entertainment/who-is-yook-sungjae/12792151) His breakthrough came in 2015 as Gong Tae-gwang in the KBS2 youth drama *Who Are You: School 2015*; later that year he took his first male lead role as Park Woo-jae in SBS's *The Village: Achiara's Secret*, earning a New Star Award at the 2015 [SBS Drama Awards](https://www.edgepedia.org/sbs-drama-awards).[4](https://asianwiki.com/Yook_Sung-Jae) • [10](https://d.namu.moe/w/%EC%9C%A1%EC%84%B1%EC%9E%AC/%ED%99%9C%EB%8F%99)
His widest mainstream exposure came as Yoo Deok-hwa in tvN's *Guardian: The Lonely and Great God* (2016–2017), one of the most-watched Korean cable dramas of its period.[2](https://www.koreajoongangdaily.com/entertainment/who-is-yook-sungjae/12792151) • [3](https://www.imdb.com/name/nm6857340/) He then led JTBC's *Mystic Pop-up Bar* (2020) as [Han Kang](https://www.edgepedia.org/han-kang)-bae and MBC's *The Golden Spoon* (2022) as Lee Seung-cheon, a poor student who swaps fates with a wealthy friend through a magical golden spoon; the role won him Best Actor at the 2022 MBC Drama Awards.[4](https://asianwiki.com/Yook_Sung-Jae) • [11](https://www.soompi.com/article/1552192wpp/btobs-yook-sungjae-reveals-his-big-career-dreams-changed-perspective-on-his-30s-and-more) In 2025 he starred as Yoon Gab in SBS's *[The Haunted Palace](https://www.edgepedia.org/the-haunted-palace-tv-series)*, winning Best Actor at the 2025 SBS Drama Awards.[4](https://asianwiki.com/Yook_Sung-Jae)
## Variety television
Yook is also known for reality and variety work. From 2015 to 2016 he appeared on MBC's *We Got Married* in a mock marriage with Joy of the girl group Red Velvet.[2](https://www.koreajoongangdaily.com/entertainment/who-is-yook-sungjae/12792151) In 2015 he competed on the singing disguise show *King of Masked Singer* as the "I'm Tired Now, Bumblebee" contestant, where both his vocals and his unmasked appearance drew wide attention.[10](https://d.namu.moe/w/%EC%9C%A1%EC%84%B1%EC%9E%AC/%ED%99%9C%EB%8F%99) From December 2017 he was a regular cast member of SBS's *[Master in the House](https://www.edgepedia.org/master-in-the-house)* (*Jipdabuilche*), winning the variety program's Excellence Award at the 2018 SBS Entertainment Awards.[12](https://agetrail.com/people/yook-sung-jae/)
## Solo music after military service
Yook enlisted for mandatory military service on May 11, 2020 and was discharged on November 14, 2021.[4](https://asianwiki.com/Yook_Sung-Jae) After returning, he resumed acting with *The Golden Spoon* in 2022 and, in December 2023, left CUBE Entertainment after 11 years and signed with iWill Media, which manages his solo work while he remains a BTOB member for group activities.[7](https://fametown.com/en/celebrity/yook-sung-jae/) • [8](https://www.soompi.com/article/1634203wpp/btobs-yook-sungjae-launches-official-x-twitter-account-after-joining-new-agency) • [13](https://hitkultr.com/artists/yook-sung-jae)
His first release under the new agency was the single album *EXHIBITION : Look Closely*, released May 9, 2024, containing three tracks: the rock-leaning title track "BE SOMEBODY", "Without you", and "The Ghost".[14](https://www.newsis.com/view/NISX20240510_0002729778) Two of the three tracks are in the rock genre, a deliberate departure from the ballad style that had defined his earlier solo work, and he co-wrote lyrics for "BE SOMEBODY" and "Without you", both of which carry substantial English lyrics.[14](https://www.newsis.com/view/NISX20240510_0002729778) He followed with the single "LIE" in May 2025 and the EP *All About Blue* in June 2025.[9](https://musicbrainz.org/artist/110a38cb-1b92-42c2-93ad-d312fa760801)
## Vocal profile
Yook's voice is generally described as a baritone, and he is one of BTOB's two lower-voiced members alongside Im Hyun-sik.[15](https://www.bloomvocal.site/en/blog/how-to-sing-like-sungjae-btob) One vocal-analysis source estimates his range at approximately B1 to G4, with some live performances suggesting chest-voice extension toward A4, while noting that reported ranges vary between sources and between live and studio takes.[15](https://www.bloomvocal.site/en/blog/how-to-sing-like-sungjae-btob) In interviews around *EXHIBITION : Look Closely*, he said he wanted to show a clearer, more refreshing tone in the higher register rather than his usual mid-to-low range.[16](https://sun-jacket-74b.notion.site/INTERVIEW-YOOK-SUNGJAE-FOR-WWD-KOREA-MAGAZINE-JUNE-ISSUE-207638a0371480f49e92e926968e55cb)
## References
1. [육성재 (Yook Sung-jae) profile, Yes24](https://www.yes24.com/product/author/167127)
2. [Who is Yook Sung-jae?, Korea JoongAng Daily](https://www.koreajoongangdaily.com/entertainment/who-is-yook-sungjae/12792151)
3. [Yook Sung-jae, IMDb](https://www.imdb.com/name/nm6857340/)
4. [Yook Sung-Jae profile and filmography, AsianWiki](https://asianwiki.com/Yook_Sung-Jae)
5. [BTOB / ソロ / 俳優 ユク・ソンジェ, SNAPSHOT](https://ksnapshot.net/btob-yooksungjae/)
6. [YOOK SUNGJAE – 'Come With The Wind' Official Music Video, BTOB Official YouTube](https://www.youtube.com/watch?v=tw63M5Putw4)
7. [Yook Sung-jae biography, Fametown](https://fametown.com/en/celebrity/yook-sung-jae/)
8. [BTOB's Yook Sungjae Launches Official X (Twitter) Account After Joining New Agency, Soompi](https://www.soompi.com/article/1634203wpp/btobs-yook-sungjae-launches-official-x-twitter-account-after-joining-new-agency)
9. [육성재 (YOOK SUNGJAE, BTOB), MusicBrainz](https://musicbrainz.org/artist/110a38cb-1b92-42c2-93ad-d312fa760801)
10. [육성재/활동 (Yook Sung-jae/Activities), Namu wiki](https://d.namu.moe/w/%EC%9C%A1%EC%84%B1%EC%9E%AC/%ED%99%9C%EB%8F%99)
11. [BTOB's Yook Sungjae Reveals His Big Career Dreams, Changed Perspective On His 30s, And More, Soompi](https://www.soompi.com/article/1552192wpp/btobs-yook-sungjae-reveals-his-big-career-dreams-changed-perspective-on-his-30s-and-more)
12. [육성재는 몇 살에 알려졌을까?, AgeTrail](https://agetrail.com/people/yook-sung-jae/)
13. [Yook Sung-jae – BTOB Singer, Soloist and Actor, HITKULTR](https://hitkultr.com/artists/yook-sung-jae)
14. [육성재, 발라드 아닌 '록' 택한 이유, Newsis](https://www.newsis.com/view/NISX20240510_0002729778)
15. [How to Sing Like Sungjae (BTOB): Vocal Range and Technique, Bloom Vocal](https://www.bloomvocal.site/en/blog/how-to-sing-like-sungjae-btob)
16. [Interview: Yook Sungjae for WWD Korea Magazine June Issue](https://sun-jacket-74b.notion.site/INTERVIEW-YOOK-SUNGJAE-FOR-WWD-KOREA-MAGAZINE-JUNE-ISSUE-207638a0371480f49e92e926968e55cb)
---
*Topic: Encyclopedia › Arts and culture › Music › Music scenes › East and Southeast Asian pop scenes › K-pop and the Korean popular music scene › Artists, groups, and people: K-pop and the Korean popular music scene › Third-generation idol groups › Surnames T to Z*
*Initially written Sep 17, 2026 · Reviewed: Sep 19, 2026; Sep 30, 2026; Oct 25, 2026 · Edited: Sep 30, 2026; Oct 12, 2026; Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license