Kabamaru (hippo's mouth) is a reference to his insatiable appetite. After the death of his strict grandfather and ninja sensei, Kabamaru moves to Tokyo with one of his grandfather’s acquaintances. The plot deals mainly with Kabamaru adjusting to an urban lifestyle after spending a childhood in the mountains and how he finds himself caught up in the rivalry between two private schools.
Igano Kabamaru has been adapted to television and film.