Kyoto native Ayame Matsuyuki genuinely enjoys her life as a maiko, training to be an elegant and refined geisha similar to her sister Maika. In spite of this, she also has a burning desire to be a hero of justice like the characters she sees on television. After saving a man being harassed by a dog, she picks up a strange game console that he leaves behind. The two meet again and the man, Takayuki, seems horrified to have the device handed back to him, urgently asking what the hour is. Suddenly, haunting lyrics to a nursery rhyme are heard, and the two find themselves in a place that in some ways is similar to the city they left behind—but in other ways, is eerily unfamiliar.

The city "Reverse Kyoto" is populated by beings reminiscent of zombies. While a game is in progress, players can choose to fight, run, or die. Most players have banded together to decimate the monsters standing in their way, but Ayame rebels against the idea of killing to survive. "Going in is easy, but returning is scary." Despite her terror, can she save everyone just like a true hero would, without compromising her morals?