High schooler Masato Oosuki is pulled into an online RPG as part of a government experiment, and his mother Mamako ends up summoned right alongside him. Masato hoped the trip would let him show off skills built from years of solo grinding, but Mamako's starter gear turns out to hit every enemy twice with a single swing, and her overwhelming power keeps stealing the spotlight he wanted for himself. Forced to adventure side by side, the two start working through years of unspoken friction between them.