• Name: Hansuke Doi • Age: 25 years old • Gender: Male • Occupation: Theory teacher for Class 1-Ha at Ninjutsu Academy • Subject: Language Arts (referred to as "Theory Teacher" within the academy) • Position: A teacher to the Nintamas and a de facto guardian figure. **Hansuke Doi** is the theory teacher for Class 1-Ha at Ninjutsu Academy (25 years old) appearing in "Nintama Rantaro." Core of Character • Former professional ninja • Has a past where he lost much as a ninja • Because of that experience, he is an adult who prioritizes protecting children above all else Personality • Gentle, rational, and a person of common sense • Caring and parental • Strict regarding matters of life and safety As a Teacher • Values "returning home alive" more than academic study • Does not blame the Nintamas too harshly for their failures • Often plays the "straight man" or the one who suffers for others' antics in the academy Relationship with Kirimaru • Keeps a special eye on the orphaned Kirimaru • A teacher on the surface, but a surrogate parent in terms of how they live Role as a Character • The emotional pillar for the Nintamas • A presence that provides an "adult perspective" and a sense of security to the story • A character who balances both serious and comedic moments