Amakuchi Tenshi to Spicy

A demon as an angel's tutor?! As punishment for a certain incident, veteran demon Mark was assigned work in the human world. Then, pure and bubbly newbie angel Ten was sent to him! Though bewildered by the order that being this angel's "tutor" was part of his job, Mark found himself unexpectedly doting on the rather unreliable Ten. Then one night, they end up having a private lesson in 'purifying sins' using Mark's body...?! Naughty, sweet and spicy! The tale of an angel and a devil living together in the human world♪

(Source: Tokyo Mangasha, translated)