Inai Boku wa Hotarumachi ni Iru

Takeru is overwhelmed by grief after his best friend Takuya's death and makes a wish upon a falling star. A flash of light guides him to an old tree stump with a large hollow inside. To his astonishment, the hole connects to a city identical to his own, with the same people and locations. However, there is a crucial distinction: in this version of the city, Takuya is alive and healthy, while Takeru does not exist.