Sekai Saikyou no Maou desuga Darei mo Toubatsushi ni Kitekurenai no de, Yuusha Ikusei Kikan ni Sennyuu suru koto ni Shimashita.

Lucifer is the strongest Demon Lord in history who ruled over the other clans with absolute power. After violating the angel and female hero who came to subjugate him and turning them into his wives, he led a sedentary lifestyle of food, sex and sleep. One day, five hundred years since the last hero came to fight, the destructive impulse in his blood compelled him to search for a strong enemy to fight. “Why aren’t there any heroes coming to subjugate me, this can’t do!” In order to investigate the academy where heroes are raised, Lucifer transformed into a human boy and entered the Elberia Empire. During the entrance examinations, he easily achieved the top position in the three areas of swordsmanship, physical ability and magic, earning him the spotlight throughout the academy…… The school life of the world’s strongest demon lord now starts!

(Source: Shogakukan, translated)