Usotsuki Sensei to Emono na Watashi

Ameya is a sensible high school girl who has multiple part-time jobs to help out with her family's finances. One day, the principal gives her an offer too good to refuse—he'll double her scholarship if she just provides a certain teacher with a meal once a week.

The catch is—Kairi-sensei is literally a demon, and his 'meal' is Ameya's touch!

(Source: MangaDex)