Patrol-kun is a talking police car existing in a world where sentient vehicles and humans coexist. He serves as a police officer in Himawari Town, partnered with human officer Hajime. Together, they patrol the streets to maintain order and address various incidents. Their collaboration starts on Patrol-kun's first day assigned to the police station. During their patrols and experiences in Himawari Town, Patrol-kun and Hajime encounter situations that foster learning life lessons together.