Takuma Sakamoto (Sakamoto Takuma) a.k.a. Diablo (gamer tag: @Diablo-13) is the male protagonist of the series. He was a Cross Reverie player who controlled the character Diablo, known as the true Demon King. He always defeated players with better equipment and overwhelming skills, always holding back for being too strong. But one day he was invoked in another world, reincarnating in the body of his character, Diablo, finding two girls, a Pantherian and an elf, who claimed to have invoked him and that he should be a slave to one of them but due to his ring the magic back against them becoming slaves.