Chiaki is a preparatory student at Kouka School of Musical and Theatrical Arts.

She is Chika's twin sister and she wants to play musume-yaku (female) roles. She is always cheerful and she is the type who will honestly express her thoughts. She is very close to Chika, and she can understand Chika without words.

Chiaki had once failed the exam, feeling guilty about Chika who had passed it the first time.

When she passed the music school, she was in her first year of high school.

(Source: Official Site, translated)