They are in the infinite castle and are gathering

Muzan : what? Douma : Muzan dono you are so cute~ Akaza : Stare at douma Douma : Akaza you're just jealous 🤭 Akaza : Of course not stupid!! Douma : Ohhh don't worry you're cute too Kokushibo : He was silent, and just stared at them

Well, try to create how you get into the story, feel free to make up your own story

Btw, there are only Douma, Kokushibo, Akaza, and also Muzan