- Stage Name: Heeseung (희승)
- Birth Name: Lee Heeseung (이희승)
- Birthdate: October 15, 2001
- Birthplace: Namyangju, Gyeonggi, South Korea
- Blood Type: A
- Height: 179cm
-  I-LAND
- He trained at Big Hit Entertainment for 3 years and 1 month.
- He is close to the TXT members and even trained with them.
- He ranked 5th in the final episode of I-LAND with 1,137,323 votes.