Happy3days

 was an idol group from Fukuchiyama, Kyoto formed in March 2016. The second generation joined on July 17, 2018.

They disbanded in April 2020, but their final concert was cancelled due to the COVID-19 pandemic.

Final Lineup

 * Usami Rui - Leader (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

 * Fukui Airi (福伊あいり; ) - Leader (Original Member; Withdrew July 9, 2016)
 * Arakawa Yuika (荒川唯香; ) (Original Member; Graduated June 3, 2018)
 * Hirate Ruko (平手瑠虹) (2nd Generation; Left November 4, 2018)
 * Moeko (萌衣子; ) (Original Member; Graduated March 30, 2019)
 * Takamatsu Yuua (高松ゆうあ; ) (Original Member; Graduated March 30, 2019)

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