Asahi Ikusaba wakes up in another world after an accident in the real world. He tries to enjoy this new world of his dreams, but it seems that his power in this world is very weak. Just as he is about to be attacked by a wild monster, Asahi's caring sister Mayu comes to his rescue and saves him. Due to her love for Asahi, Mayu also wakes up in the same world with the strongest abilities and cunning skills. Thus begins the fantastic story of a strong sister with a brother complex and her weak brother.
