Verta the green snake-demon must find a way to escape from the modern Shura City of mortals, in order to rescue her elder sister Blanca the white snake from the demon-slaying monk Fahai without her demonic abilities.

Verta wakes up, without her demonic powers, in a modern dystopian city called Asuraville, a place that imprisons creatures from many different eras.

She meets a woman named Sun, who helps her adjust to the modern world, and a mysterious masked man with amnesia, who saves them.

The main enemies in Asuraville are an army of Ox-Heads & Horse-Faces, led by the Ox Leader who seeks to conquer the city.

The only way to leave is to let it go by discarding their token and jumping into the Pool of Release, but it makes you forget what you cared about and drains your will.

While outrunning some evil spirits, the masked man gets stuck and Verta tries to help him, but Simon abandons them upon seeing them as dead weight.

Verta learns a lesson that in love strength doesn’t matter, having a good heart does, accepting that her sister was right.

In the tunnel, she battles Fahai for 20 years (1 day in Asuraville) until she kills him and destroys the Pagoda, thus ensuring Blanca's freedom in the human world.

When they almost don't make it, the masked man lets himself become an evil spirit so he can fly Verta to the exit, sacrificing himself.