ゲーム内での圧倒的強さから『魔王』と他プレイヤーから恐れられる坂本拓真が眠りから目覚めると、眼前には「私こそ召喚主」と言い張る美少女２人と、見慣れたゲームそっくりの世界が…。コミュ力０の主人公は、ゲームで培った能力とロールプレイで異世界の魔王『ディアヴロ』となり突き進む!!

In the MMORPG Cross Reverie, Takuma Sakamoto is so powerful that he is lauded as the “Demon Lord” by other players. One day, he is summoned to a world outside his own– but with the same appearance he had in the game! There, he meets two girls who both proclaim themselves to be his Summoner. They perform an Enslavement Ritual to turn him into their Summon… but that’s when Takuma’s passive ability <<Magic Reflection>> activates! Instead, it is the girls who become enslaved! Though Takuma may be the strongest Sorcerer there is, he has no idea how to talk with other people. It is here he makes his choice: to act based on his persona from the game! “Amazing? But of course… I am Diablo, the being known and feared as the Demon Lord!” So begins a tale of adventure with an earth-shakingly powerful Demon Lord (or at least someone who acts like one) taking on another world!