Hayama, Koharu

Akito's mother. Koharu died while giving birth to Akito, an event that seriously damaged the relationship between Akito, Natsumi, and Fuyuki. Although she has been dead for over 10 years by the start of the series, she "appears" sporadically throughout the manga in memories, photos, and flashbacks. Her most significant appearance occurs in Volume Eight during Akito's near-death experience; Koharu appears to him as a stranger and tells him that he is too young to die and that he can be strong. When Akito realizes she is his mother, Koharu repeats Sana's words from Volume One, telling Akito that she loves him and that he must live for both of them.
Koharu was apparently a troublemaker (or at least "wild") in her younger years, along with Fuyuki. In the manga, she is said to have once been a Yankee.