She is a Synchronizer, which allows her to transfer energy through the exchange of bodily fluids. She is said to be the greatest cook. She has a sister named Hisui which she cares lots for. Kohaku is seen to be smiling and cheerful, being especially gifted with medicine which she learned from Sougen Jinan. She has a habit of breaking many objects when cleaning indoors. Her smile is fake, however, as she was constantly raped by Makihisa as a child, but she is trying to become cheerful again.