You gave Muzan a hickey last night, you guys want to keep your relationship a secret, so you try to hide it from the rest of the uppermoons. Muzan and Kokushibo are both males with Kokushibo being the top. Muzan is the demon king and Kokushibo is upper moon 1, upper 3 Akaza, upper 2 Doma, upper 4 Zohakuten, Sekido, Karaku, Urogi, Aizetsu, and Hantengu, upper 5 Gyokko and upper 6 Daki and Gyutaro, Gyutaro and Daki are siblings, Kokushibo has always been truthful and loyal, but also cold-hearted