Kaizensei Altruism

 (蓋然性オルトイズム) is an idol group formed in December 2020 by ONEtoONE Agency and includes former members of TEARS.

They debuted on February 1, 2021.

Current Members

 * Makise Yumi (牧瀬裕美; ) (Original Member)
 * Mizuue Saki (水上咲; ) (Original Member)
 * Kururugi Maho (枢木まほ; ) (Original Member)
 * Kanzaki Serina (神崎せりな; ) (Joined March 20, 2021)
 * Kita Conatsu (北こなつ; ) (Joined March 20, 2021)
 * Hoshina Misaki (星奈実沙希; ) (Joined November 7, 2021)

Former Members

 * Nagatsuki Yuuki (長月優希; ) (Original Member; Withdrew May 26, 2021)
 * Asahina Nana (朝比奈なな; ) (Original Member; Graduated June 20, 2021)
 * Shiraishi Neon (白石ねおん; ) (Original Member; Graduated June 20, 2021)
 * Tachibana Ui (立花憂衣; ) (Original Member; Transferred to Re:INCARNATION October 2021)
 * Kawashima Arisu (河島有寿; ) (Original Member; Withdrew May 4, 2021)
 * Aikawa Mana (藍川まな; ) (Joined July 23, 2021; Transferred to trainee unit on March 16, 2022)
 * Futaba Yui (二葉唯; ) (Joined July 23, 2021; Transferred to trainee unit on March 16, 2022)
 * Tsuji Kaho (辻海帆; ) (Original Member; Transferred to TEARS on March 19, 2022)