Alto is the male protagonist of the Kinsou no Vermeil series. He is the one who summoned the most powerful devil of all time, [Vermeil](https://anilist.co/character/171759).
Apparence
Kinsou no Vermeil: Gakeppuchi Majutsushi wa Saikyou no Yakusai to Mahou Sekai wo Tsuki Susumu