Kozue has been Kū's best friend since they were little and always keeps her in mind. She has her energy drained from her by Tarlotte during one of the latter's attacks on the school Kozue attends along with Kū. She has a fascination with Jin Ōgami. She remains concerned with Kū's well-being after the latter disappears and tries to contact her, though Kū is unaware of this and believes her place at Kozue's side has been taken. Neither of Kozue's parents are with her.
Kozue has short black hair barely reaching the base of her neck, framed by bulky red goggles that seem to always be resting atop her head. Her eyes are brown and she isn't especially tan, and most commonly can be found wearing her school uniform.
Kū Shiratori - Kozue's very best friend since a very young age, the two girls having been extremely close, evidently. So much so that Kozue, upon noting her friend's apparent depression over not having anyone seem interested in taking her as their date to the dance, offered to take her instead.
- The name Kozue actually means 'treetop; tree branches'. You could say that catching wind of Kū's problems really rustled her branches.