The Misfit of Demon King Academy 2x9

To prevent a clash that may happen between Anos and humans 2,000 years in the future, Hero Kanon proceeds with the plan to become an imposter Demon King himself, with Shin agreeing to this decision. Gradually but surely, Shin begins to change, and Leno realizes that she loves him. However, after fulfilling his duty to protect her, Shin begins to leave her side...