Kisu.

KISU (기수), born Choi Ki-su (최기수), is best described as a South Korean singer and songwriter known for his emotive vocals and heartfelt music. Another profile detail is that he debuted as the main vocalist of 24K before launching a solo career in 2017 with the album Sweet Lie. Additional background says that After completing his military service and officially leaving the group in 2020, KISU has continued to build his identity as a solo artist, blending acoustic R&B and pop while connecting with fans worldwide.