Little Choo wants to be just like his father Papa Pufferbelly, but pulling a line of freight cars up a steep mountain might be a little too much for the small engine.

A hungry cat gets a job hunting mice at a sumo training center, but once the mice are gone he continues to stuff himself until he is too fat to chase the mice that have returned--so he decides to train with the sumo wrestlers, and SumoKitty becomes a scourge of mice and an inspiration to the wrestlers.