Tanuki serves as principal of the middle school in Matsuyama where Botchan teaches mathematics. His actual name is never revealed; he is identified solely by the nickname "Tanuki," given by Botchan based on the foolish and amusing Japanese folklore trickster known for feigning sleep when threatened.

Mild-mannered and indecisive, Tanuki frequently avoids directly intervening in staff conflicts. He maintains professional decorum and prizes protocol, yet this masks an ineffectual leadership style. He prefers to let situations resolve themselves without action, leaving him easily manipulated by subordinates like the assistant principal, Red Shirt, who influences decisions behind the scenes.

As principal, Tanuki prioritizes surface harmony over confronting underlying misconduct. Functioning more as a figurehead than an authority, he allows power struggles among teachers to escalate unchecked. This administrative passivity fosters an environment where schemes against colleagues proceed without consequence.

Tanuki embodies institutional ineffectuality within the educational system. His consistent avoidance of decisive action indirectly enables the central conflicts involving Botchan and other staff. The nickname "Tanuki" perfectly captures his perceived role: a passive observer who retreats from challenges rather than confronting them.