Kana Arima「有あり馬ま かな, Arima Kana?」 is a major supporting character in Oshi no Ko. She is a childhood acquaintance of Aqua and Ruby Hoshino and a prodigious child actress, though her popularity has waned over the years. She is also the center of the revived idol group B-Komachi.

Though talented, she eventually got fewer jobs due to being difficult to work with, causing her to change her acting style to survive in the industry. However, after meeting Aqua and Ruby again and being recruited into B-Komachi as well as through her rivalry with Akane Kurokawa, she steadily began to undo the shackles she placed on herself.