Patrol-kun is a talking police car, existing in a world where talking vehicles and humans live together. He starts his first day at a police station meeting up with his partner, a human police recruit by the name of Hajime. Together, they patrol the streets of Tokyo, learning various life lessons along the way.

Ginya Otonashi is a college dropout who works part-time for a pachislot publishing company while aspiring to become a novelist. One day, Ginya comes across a secret organization and gets pulled into a competition to become #1 in "Pachi Battle," which is all a part of the Slotseum, a pachislot competition.