Kohaku is Kohane Azusawa's older sister by a year, she's laid back and mellow but will get irritated from time to time and can be cold hearted and grumpy, often if a boy tries hitting on her too many times like Akito Shinonome. She's childhood best friends with Mizuki Akiyama, and is quite close to her fellow classmate, Rui Kamishiro. Her laid back and grumpy mood often vanishes if she's given cake or is around her sister. She's a member of kamiyama's volleyball team, and is one of the captains.