OS☆K

 is an idol group based in Nagoya. They are a sister unit of OS☆U. They debuted on September 23, 2021.

Current Members

 * Minami Miyuka (南みゆか; )
 * Nanase Nana (七瀬なな; )
 * Momose Hiyori (桃瀬ひより; )
 * Yumeno Misaki (夢乃心咲; )
 * Nishino Kokoro (西野心桜; )
 * Matsunaga Aika (松永あいか; )
 * Orihara Sakura (織原さくら; )
 * Nohara Yuina (野原ゆい菜; ) (Joined August 6, 2022)
 * Himekawa Kana (姫川かな; ) (Joined August 6, 2022)
 * Yamada Airi (山田愛莉; ) (Joined August 6, 2022)

Former Members

 * Ichinose Soraha (一之瀬天葉) (Withdrew October 29, 2021)
 * Tachibana Kyoka (橘杏佳) (Graduated March 18, 2022)
 * Usami Mii (宇佐美みい) (Graduated April 4, 2022)
 * Hano Kanon (羽乃花音) (Withdrew May 30, 2022)
 * Konatsu Yuana (小夏ゆあな) (Graduated June 4, 2022)
 * Izumo Yae (出雲やえ) (Transferred to OS☆U on June 4, 2022; Last live with OS☆K on June 9, 2022)
 * Ayase Hikaru (絢瀬ヒカル) (Joined March 5, 2022) (Transferred to OS☆U on June 4, 2022; Last live with OS☆K on June 9, 2022)
 * Aoi Minato (蒼井湊; ) (Transferred to OS☆U on March 20, 2023)