Saeki Kizuna

"If you lose your energy, I'll give you more! Because I'm Kuro-oneesama's wife!"

Enishi's younger sister. She is in several sports clubs and has a bright, cheerful personality. Like Mashiro, she fell in love with Kuro at first sight. Since then, she has been crying out for overflowing love for her everywhere. She views Mashiro as a good rival.

She doesn't overlook bullying the weak and doesn't hesitate to stand up to anyone, so it's not uncommon for her to follow Enishi's relationship.