attack! Two-dimensional heroines

Yukino: Chosen as a Hero
Darkness: Chosen as a pervert
Kato Megumi: Chosen as a Hero
Shijo Zhenfei: Called to be a Hero
Kirino: Called to be a hero....
What about Nangong Yeyue, who is a demon king (and a restricted painter)?
How to keep them from affecting his grand plan - to turn reality and a different world into his desire
Answer: Disguise yourself as a full-level hero, mix in with them, take them to level up and brush yourself up, fill up your favorability, and just become a wife.