Nodaiko Yoshikawa, nicknamed "Clown" and "Field Radish," is the art teacher at the protagonist’s middle school. A fellow Tokyo native, he contrasts the protagonist through his relentless prioritization of flattery and subservience to authority over independent judgment. His obsequious loyalty to Red Shirt, the manipulative head teacher, cements him as a willing accomplice in schemes targeting colleagues, particularly efforts to destabilize the protagonist and his ally Porcupine.

Yoshikawa actively advances Red Shirt’s agendas by disseminating misinformation to breed distrust and coercively influencing administrative rulings. He collaborates in fabricating evidence against the protagonist and Porcupine during a staged student conflict, seeking to pressure their resignations. His nicknames encapsulate his sycophantic identity and theatrical ingratiation, mirroring traditional male geisha who navigate social hierarchies through performative compliance. As a steadfast secondary antagonist, his maneuvers underscore the institutional clash between moral principle and corrupt opportunism within the school’s power structure.