Miroku — the fearsome yōkai known as the slit-mouth woman—finds her powers fading as humans stop believing in the supernatural. Wikipedia +2 even-if-you-slit-my-mouth.fandom.com +2 To restore her strength she becomes engaged to Kōichi Sano, a high-schooler from a family that supports supernatural beings. Anime Planet +1 They strike a precarious deal: if Miroku fails to scare Kōichi before his 18th birthday, the engagement stands—and yet Kōichi’s surprising earnestness draws her into something deeper than just a contract. mangapill.com What begins as a supernatural survival tactic turns into a heart-warming tale of trust, change and unexpected romance.