Diablo (Takuma Sakamoto)

Diablo (also known as Takuma Sakamoto) is the main protagonist of the anime How NOT to Summon a Demon Lord (original title: Isekai Maou to Shoukan Shoujo no Dorei Majutsu).

He is a reclusive, socially anxious Japanese gamer and hikikomori who was an elite player in the MMORPG Cross Reverie, where he role-played as the overwhelmingly powerful Demon Lord character named Diablo — feared as the "true Demon King" for dominating other players with superior gear, skills, and strategy.

One day, he gets isekai'd (transported) into a fantasy world that closely resembles his game, appearing in the body of his max-level Demon Lord avatar: a white-haired demon with horns, sharp features, immense magical power, and a dramatic, imposing presence.

Two girls — the Pantherian Rem and the elf Shera — summon him intending to enslave him as their servant/familiar to help with their own problems, but his in-game magic-reflecting ring causes their enslavement spell to backfire. Instead, they end up collared as his slaves.

Due to his extreme social anxiety and inability to talk normally to people (especially women), Takuma fully commits to acting as the arrogant, over-the-top "Demon Lord Diablo" persona in public — complete with booming declarations like "I am Diablo, a Demon Lord from another world!" — while internally panicking and being kind-hearted underneath.

The story follows him using his game knowledge and OP abilities to protect Rem and Shera, help remove their collars, deal with various threats, and navigate the fantasy world, all while maintaining his intimidating facade.