Ono Akira (voiced by Kenjiro Tsuda) is a game operator. One day, when he logged into the account of the final boss of the game, the demon king Kunei Boto, he accidentally crossed into a different world in the game, and he was in the identity and image of a demon king. In this way, Ono Akira began to explore the game and met the very weak Ako (voiced by Takao Kanon). Ono Akira knew that Ako could not survive in this world of the jungle, so he decided to protect her. In this way, Ako became the "heroine". Since he is a demon king, there must be many brave men around Ono Akira who want to get rid of him as soon as possible. What kind of interesting story will happen when the three saints appear beside Ono Akira, the arrogant and willful saint Luna (voiced by Ishihara Natsuki), the rough but delicate Kira (voiced by Tomatsu Haruka), and the mature and steady Angel (voiced by Toyosaki Aki)?