Takuma Sakamoto, a socially withdrawn gamer, is mysteriously summoned to a fantasy world appearing as his Demon Lord game character, Diablo.
Takuma meets the two girls, Rem Galleu and Shera L. Greenwood, who summoned him, and they begin their journey together.
Takuma (as Diablo) explores the new world and practices using his powerful magic abilities more seriously beyond just gaming knowledge.
Diablo and his party defeat the dangerous Soul Eater Spider monster threatening the nearby village.
The party expands to include Edelgard and Sylvie, skilled adventurers who join Diablo's group.
Diablo faces Mephisto Pheles, a powerful and mysterious demon lord who challenges his authority and power.
Rem Galleu's identity and powers as a Pantherian and a summoner are fully revealed, deepening the group's understanding.
The group ventures into the demon world itself to confront greater threats and find answers about Diablo's powers.
Diablo and his allies take on the combined forces of the Demon Lords' council to protect the human and demon worlds.
