Summary: Muzan may have not conquered the sun, But he can own that pure Sunshine instead. In exchange of not killing his friends, Tanjiro decided to go with Muzan. Now the Twelve Demons wanted to be friends with him, or because he is the favorite of their beloved Muzan-sama. Tanjiro slowly breaking or actually falling for this Demon?! WARNING MATURE CONTENT/Muzan X Tanjiro! Romance (Tanjiro is in this story 18!)