YU-NO: A girl who chants love at the bound of this world.

Takuya Arima's father, a historian, vanished recently, leaving behind a mysterious package for his son. The package included a letter detailing the concept of parallel worlds, which initially seemed like science fiction to Takuya. However, he soon discovered that he had a device in his possession that allowed him to travel to alternate dimensions, raising questions about his father's disappearance and potential whereabouts.