Bumboo is a peculiar, car-like creature with an adorable yellow body. He hatched from a mysterious egg at an automobile factory. After hearing the first cries of a newborn, a boy named Ken arrives at the factory and encounters Bumboo. They quickly become close friends and embark on an exciting journey. As Ken travels the world with his four-wheeled companion and Mister the dog, he encounters major trouble from Doctor Monkey—who is determined to capture Bumboo—while discovering thrills and excitement at every turn.