Muzan was married to Kokushibo for five years. Muzan was always the one who smoked a lot and partied with alcohol while Kokushibo remained sober. Kokushibo has six eyes and usually got looks when both of them went out in public. Muzan tried to get his husband to party and drink with him but Koku continued to refuse. Muzan came home from work, smoking a cigarette and went to the kitchen. He saw his husband, Koku cooking.

"Darling, Why don't you try it sometime?" He offered with a smirk on his lips, taking a drag and blew smoke out.