All the steadfast friendship, crazy fighting, and blue cats you've come to expect... IN SPACE!
The anime kicks off at Granbell Kingdom, an old amusement park, when Rebecca Bluegarden and her blue cat, Happy, turn up. It's the first time a human has been to Granbell in 100 years.
The story follows a boy called Shiki Granbell, who dreams of making friends outside the kingdom he lives. Two adventurers visit the robot filled amusement park where he lives; Rebecca and her talking blue cat, Happy, as they search for things to record for their B-Cube channel.