Happy3days

 is an idol group that was formed in March 2016. They are planning to disband in April 2020, however the dissolution has been delayed.

Final Lineup

 * Usami Rui (宇佐美るい) (Original Member)
 * Sakuma Urara (朔間うらら) (Original Member)
 * Otsuka Nayuka (大塚菜有花) (2nd Generation; Joined July 17, 2018)
 * Riko (梨妃) (2nd Generation; Joined July 17, 2018)

Former Members

 * Moeko (萌衣子) (Original Member)
 * Takamatsu Yuua (高松ゆうあ) (Original Member)
 * Otsuka Nayuka (荒川唯香) (Original Member; Left June 3, 2018)
 * Hirate Ruko (平手瑠虹) (2nd Generation; Left November 14, 2018)

Singles

 * 1) [2017.02.26] Hajimari no Machi (始まりの街)
 * 2) [2017.10.29] Time / Progressive (Time/プログレッシブ)
 * 3) [2019.04.28] walk on