BSS (부석순)

BSS, also known as BooSeokSoon (부석순), is the official sub-unit of South Korean group Seventeen, formed under Pledis Entertainment. The unit consists of three Seventeen members — Seungkwan, DK, and Hoshi — with the name derived from syllables of their real names: Boo (Seungkwan), Seok (DK, born Lee Seok-min), and Soon (Hoshi, born Kwon Soon-young). All three are known within Seventeen's «Performance» and «Vocal» teams, and BSS lets them explore material outside the full group's dynamic, often leaning into more mature, groove-oriented pop and R&B.

The unit debuted in March 2018 with the single «거침없이 (Just Do It)», establishing a sound distinct from Seventeen's broader discography. BSS returned in force with the single album «SECOND WIND» in February 2023, featuring the breakout hit «파이팅 해야지 (Fighting)», which became a commercial and streaming success and showcased the trio's chemistry and vocal blend. They followed with «청바지 (CBZ) (Prime time)» and other tracks that leaned into warm, mid-tempo grooves.

In January 2025, BSS released their second single album, «TELEPARTY», continuing to build a catalog defined by smooth vocal interplay, playful charisma, and R&B-inflected pop production. As one of Seventeen's most consistently active sub-units, BSS occupies an important place in the group's broader ecosystem, giving fans a distinct, vocally-focused counterpart to Seventeen's larger-scale releases.