A young child resides on Monster Island among other monsters, all portrayed as young children living together as friends. Mothra, the only adult, acts as a maternal figure to the group and raises her own twin larvae.

This character frequently argues with his best friend, Anguirus, and these conflicts often drive the plot. He interacts with Mechagodzilla, a lonely figure desperate for companionship who exists outside the core friend group. Mechagodzilla's attempts to kidnap the others to force friendship necessitate rescue missions. Despite these actions, his fundamental need for connection leads to his eventual acceptance into the group as a friend once the captured monsters are safe.

An older version of the character appears in live-action segments with a human sister in a domestic setting, where he recounts stories of his childhood on Monster Island. These tales are then visualized through animated adventures.

These animated adventures are primarily educational, with the character and his friends learning about academic subjects together, including the hiragana alphabet, counting, and the mathematical operations of addition and subtraction.

A pink female Godzilla named Gojirin, who has heart-shaped scutes on her back, appears as a love interest.