Murai no Koi

The story tells a romantic comedy between Tanaka, a high school teacher who loves otome games, and Murai, a high school boy who is in love with Tanaka. Tanaka, who has never been involved in a real-life romance, is confessed to by Murai but rejects his confession. On the next day, Murai transforms himself into the exact likeness of Tanaka's favorite character from her favorite otome game.

(Source: Crunchyroll)