Happy Ending is the first mini-album by DIA. It will be released on June 14, 2016 with "On The Road" serving as the album's title track.
It is the first release after Eunchae joined the group and Seunghee left them after her contract ended in April. The release also marks Chaeyeon's return after I.O.I's promotions for their debut album ended on June 4, with I.O.I promoting in sub-units before she returned to promote with the group until their 1-year contract with YMC Entertainment ended.
- "Happy Ending" - 3:17
- "On The Road (그 길에서)" - 3:22
- "The Trainee (연습생)" - 4:16
- "Waiting For You (널 기다려)" (Yebin solo) - 3:02
- "Remember (기억할게요)" (Eunchae solo) - 3:02
- "Waiting For You (DIA ver.)" - 3:21
- "On The Road (Inst.)" - 3:22