On the planet of Granbell, Shiki has led an isolated life growing up as the only human in Granbell Kingdom—an amusement park operated by machines. However, that changes when Rebecca Bluegarden and her feline companion Happy arrive, unaware that they are the first to visit this abandoned amusement park in one hundred years. Hoping to make fun videos for their B-Cube channel, they instead find and befriend the socially awkward Shiki. When the machines make Granbell too dangerous for them, the trio flee and return to Rebecca and Happy's home planet, Blue Garden. There, Shiki registers as an adventurer for the Shooting Starlight guild and learns about the mysterious goddess, Mother. Curious about the familiar feeling he gets from her, he decides to set out on a journey to find her, a feat no