Akira Oono, a regular office worker, oversees the MMORPG Infinity Game. After fifteen years, he chooses to end the game by shutting down its servers. However, at midnight, he inexplicably wakes up in the body of Hakuto Kunai, the Demon Lord within Infinity Game. Witnessing a demon chasing a young girl named Aku, Hakuto defeats it effortlessly but is puzzled by the unfamiliar characters in his world. Uncertain of his situation, Hakuto, now in a foreign realm, embarks on a mission with Aku to unravel the mystery behind his unexpected presence, inadvertently causing turmoil as they journey through the fantasy realm.