Rodeo is an ordinary high school student whose greatest ambition is to become a rock star. His life takes a strange turn when he is suddenly approached by Gra-P, a peculiar creature who claims to be a music producer from the future. With Gra-P’s promise to turn him into a star, Rodeo embarks on a comedic and musical journey, striving to achieve the fame of the real-life musical duo GRANRODEO.

The central relationship in the series is the mentorship between the enthusiastic but unconventional producer Gra-P and the aspiring but inexperienced Rodeo. Gra-P, whose body has become distorted from excessive time travel, uses his futuristic knowledge to guide Rodeo, although his methods are often questionable. In one episode, Gra-P suggests a strange hairstyle, claiming it is fashionable in the future, only to laugh about it with Rodeo's mother. Another episode shows Gra-P initially mocking Rodeo for claiming his voice is his only instrument, then proceeding to teach him how to play the guitar. Rodeo, for his part, is a straightforward and honest student who begrudgingly follows Gra-P's peculiar instructions.

The cast of characters includes Rodeo’s supportive mother, Madako, who invites Gra-P to dinner and is amused by her son's unusual haircut. Rodeo also has a close friend nicknamed Tanpan, as well as classmates like the kind-hearted Futooushuu, a pudgy boy with a handsome personality who plays basketball, and Kuroko, a girl with a dark complexion who is Rodeo's love interest. Each episode is a short, two-minute segment focusing on the humorous and lighthearted interactions as Gra-P attempts to mold Rodeo into a rock star. The series continued with a second season that aired from July to December 2016.