Light and Yomi spend their days blissfully playing video games in the series. Light receives an invitation from Alpha, a messenger for someone titled King, one night when everyone else is sleeping. Light and Yomi are then transported to another realm, where they must go on a journey to save Princess Melody from the demon ruler. Light believes this is his destiny, but Yomi finds it bothersome. To begin their mission, they create a party with Alpha. Alpha, it turns out, is an AI robot with a software that allows them to level up while steadily continuing their quest.