Birth Name: Cho Seong Il 조성일

Position: Leader, Dancer, Vocalist

Birthday: March 24, 2004

MBTI: ESFJ

- On January 18, 2023 he was revealed as a member of 82MAJOR.
- His nickname is Luna (Twin is Sunny).
- A keyword to describe him is a good friend.
- Some of his favorite songs are Huh Yunjin's "I ≠ DOLL", EXO Kai's "음 (Mmmh)", and BSS's "파이팅 해야지 (Fighting)".
- Seongil is the mood maker of the group.
- His charm points are his laugh and ability to empathize with others.
- Two things he does before going to bed is praying and setting his alarm