Maou-sama wa Kaifuku Majutsu wo Kiwametai ~Sono Seijo, Sekai Saikyou ni Tsuki~

Demon King Ruburuvim lived for over 1,000 years, mastering every possible magical theory. To conquer the one thing he couldn't master in his entire lifetime—Recovery Magic—he has been reincarnated as a young girl!! It turns out that the key to mastering Recovery Magic is... making friends—!? The former Demon King, a slightly clueless "beginner" at being human, is about to dominate(?) academy life! (Source: Hifum...