At Granbell Kingdom, an abandoned amusement park, Shiki has lived his entire life among machines. But one day, Rebecca and her cat companion Happy appear at the park’s front gates. Little do these newcomers know that this is the first human contact Granbell has had in a hundred years!

As Shiki stumbles his way into making new friends, his former neighbors stir at an opportunity for a robo-rebellion… And when his old homeland becomes too dangerous, Shiki must join Rebecca and Happy on their spaceship and escape into the boundless cosmos.