There are countless other worlds, and countless Heroes summoned to save them. But what happens after the Hero wins? Some return home. Others remain behind, armed with overwhelming abilities that were useful when the world needed saving but become terrifying once the crisis is over. Eventually, the very Hero who saved a world can become its greatest threat. That's where Nagisa Sunahara comes in. Nagisa is a high school girl with an unusual after-school job: traveling between worlds and sending troublesome former Heroes back where they came from. Then her classmate Yuko Izumisawa accidentally gets dragged along during one of Nagisa's transfers. With no immediate way home, Yuko reluctantly becomes her partner. Together, the two girls begin traveling from world to world, encountering the aftermath of familiar isekai fantasies. One world has been transformed by a Hero blessed with overwhelming physical abilities. Another faces the consequences of modern medical knowledge introduced without regard for the society surrounding it. Elsewhere, even something as innocuous as hot springs can become a world-changing “cheat.” The Heroes were summoned to save these worlds, but the powers and knowledge that made them saviors can just as easily bring about catastrophe. Nagisa and Yuko's job is to prevent that final bad ending, even if it means confronting the very people everyone once called Heroes. But as the pair continue their journey, they discover an even greater threat moving between worlds: a mysterious group of “Demon Kings” who kill the Heroes Nagisa is trying to save and destroy the worlds they leave behind. An interdimensional fantasy adventure exploring what happens after the usual isekai story ends, following two high school girls tasked with cleaning up the consequences left behind by overpowered Heroes.