The main heroine of [[Tales of Hearts]], and [[Hisui Hearts]]'s younger sister. Kohaku is a kind girl but also a trained martial artist, and won't hesitate to use her skills to end squabbles between Hisui and [[kor meteor|Shing]]. Kohaku and Shing each gain a crush on each other, which irritates Hisui to no end.

She makes her first English appearance as a cameo boss character in [[Tales of Graces]] ƒ, where her name is translated to [b]Amber[/b].