18th Letter – 내 잘못이야 (Feat. J.breath(제이브리스))
Release Date: 2018.12.19
18th Letter – 알바끝나고 집에 간다며
Release Date: 2019.01.18
18th Letter – 비교하게 돼
Release Date: 2019.05.18
18th Letter – 첫 연애, 첫 이별
Release Date: 2018.01.29
18th Letter – 언제나 우리둘
Release Date: 2018.04.18
18th Letter – 넌 별
Release Date: 2018.10.11
18th Letter – 잊을게
Release Date: 2018.06.18