Tsumiki Kokoro (積木こころ) is a founding member and the leader of AiVER., a former founding member and leader of Reimei no Waka and a former founding member of JOHMMYS (As Igawa Kokoro (伊河こころ)).
After Reimei no Waka disbanded she joined JOHMMYS with fellow member Sakura Fuuka, so that she could focus on her dancing. They disbanded in February 2023, joining then AiVER., reuniting with Hazuki Miu and Matsui Yui.
