Kou is a childish and friendly raptor. Though it's gender is ambiguous, it's seen as feminine. (Obvious from appearance). Kou's original name is unknown, but was given the name "Kou" from his/her big mouth and sharp teeth. (Kou being Chinese for the word "mouth"). Kou also enjoys to laugh, and make everyone around him/her laugh, and is generally very silly and lovable.

Not much is known from his/her past, but Kou seems to be a hero at heart.