Araidoki.

"You... Are No Human!" That's how it started, when the hero Kazutoki Arai was taken completely off guard by Miharu Hijiri, who just transferred to his high school. Hijiri's true identity is an angel, with a mission to destroy demons and yokais secretly living in the human world. This can only mean one thing... Kazutoki is one of them. The angel has Kazutoki in her sights; where will his destiny lead!? It's an other-worldly comedy like never seen before. Don't miss it!!

(Source: Manga Box)