You're Being Summoned, Azazel

Ascend! The Demon Detective, The Demon and the Job (1x1)

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After finding out her husband was cheating on her, a client seeks the help of demon detective Akutabe and his new assistant Rinko Sakuma to make him stop. Akutabe summons Azazel for the task, but he fails two times. To encourage him, he entices Azazel by canceling their contract if he succeeds. He finally does by making the cheater impotent from a suggestion made by Rinko. In the end, Akutabe ends their contract but forces a contract between Rinko and Azazel.