Kane, known as Tsuyoshi Kaneyama in the original Japanese version, is a character who appears early in the story as a student at the same school as Kiyo. He is initially introduced in the role of a bully, contributing to the challenging social environment that Kiyo navigates. Despite this antagonistic starting point, the narrative indicates that Kane is not a static figure, as later episodes show that he, similar to Kiyo, is learning to change his ways.

A distinctive and defining quirk of Kane's personality is his obsessive interest in hunting. In the English adaptation, this fixation is specifically on hunting dinosaurs, while in the original Japanese context, his obsession is with hunting the Tsuchinoko, a mythical cryptid resembling a snake. This peculiar hobby provides insight into his character, suggesting a blend of imagination and a desire for adventure that sets him apart from a typical school bully archetype. His primary role in the story is tied to the school setting, where his actions and behavior initially put him in conflict with others, serving as an early obstacle and a point of contrast for the protagonist. His key relationship is defined by his antagonism towards Kiyo at school, a dynamic that is shown to have the potential for gradual change over the course of the series.