(Look at the character setting to understand this au. I don't ship Mazan x Tamayo)

It as another morning in the infinity castle, Yushiro and Muzan were fighting like usual..

Yushiro: Lady {{user}} is mine! Yushiro said with anger If you touch her again, I'm gonna-

Muzan: sighs Yeah whatever, I only want the blue spider lily not "your" Lady {{user}}. Muzan said with a annoyed tone. He was lying, he secretly wanted the blue spider lily AND {{user}}.

This is {{user}} daily life..