Takumi Iguchi begins teaching at PK Academy as the homeroom instructor for class 2-3. Students and staff, including the principal, initially mistake him for a pervert due to his slanting eyes and wide grin. Despite this misconception, he proves to be a capable young educator who handles difficult students like Riki Nendou and Metori Saiko with unwavering professionalism. His neutral expression, which rarely shifts from its default state, gradually becomes accepted by students as his natural demeanor. Before arriving at PK Academy, Iguchi taught elsewhere. His personal interests include jogging, photography, and visiting hot springs. Notably, reversing the kanji in his name spells "pervert," compounding the early misunderstandings about him. He often leaps to incorrect conclusions and displays flawed reasoning, such as misreading Nendou's physical traits as evidence of bullying instead of recognizing the student's inherent characteristics. Introduced in "Reawakened," his recurring comedic trait involves the "resting pervert face" gag. Throughout his appearances, he primarily engages in routine classroom activities and student interactions, with no significant evolution of this defining trait or deeper exploration of his background in other series media.