Oni no Hanayome wa Taberaretai

When she was young, Mashiro's life was saved by an oni. Turning 17, the ripe age to be eaten, she goes to marry him. However, he ends up doting on her excessively and has no intention to eat her?! The story of two unconsciously lovey-dovey newlyweds.

(Source: Hakusensha, translated)