On the night of his favorite game's shutdown, Akira Oono awakens in the body of his online character: Demon Lord Hakuto Kunai.

After his father was killed in an accident and his sister was injured, Shun Tokinoya works at an esports cafe. While the cafe is in debt, he and his friends hope to win the "Xaxerion Championship" in order to repay their debts.

As a result of an accident in the real world, Asahi Ikusaba is transported to another world. He tries to enjoy the different world he imagined, but his abilities prove to be the weakest. Just as he's about to be attacked by a vicious monster, Asahi's doting elder sister Maya comes into his rescue and saves him. Chasing after Asahi's love, Maya too ended up in the same world as him, with the strongest of abilities and cheat skills. The fantasy tale of the strongest elder sister with a brother complex and the younger brother with the weakest skills begins.