Masataka Sawatari, nicknamed “Waseda” after his alma mater, balances dual roles as a mathematics teacher and homeroom instructor at Sainotama Girls’ High School. Initially guiding Class 1-2 before shifting to Class 2-2, the 27-year-old educator sports gray hair, gray eyes, and fragile glasses prone to shattering during clashes with eccentric students like Minami “Yamai” Yamamoto, whose chunibyo antics test his composure. Openly candid about his attraction to female college students, he contextualizes this preference within Japan’s legal frameworks during classroom discussions, yet enforces discipline with measured professionalism against disruptions from students such as Nozomu “Baka” Tanaka.

Beyond academia, he secretly produces Vocaloid music as “Teishotoku-P,” an identity concealed from peers but peripherally intersecting with school life when student Akane “Wota” Kikuchi—an aspiring manga artist—engages with his work. His covert creative pursuits occasionally draw him into Vocaloid fan events, blurring the lines between his public and private personas.

Subtle narrative cues in the manga hint at potential romantic ties to Akane, echoing meta-textual parallels to the author’s experiences, though adaptations prioritize his academic focus. Whether addressing Yamai’s failing grades or tempering Baka’s chaos, his interactions blend exasperation with steadfast mentorship. Across all media, his deadpan demeanor and Waseda University pedigree anchor a layered portrayal of an educator juggling classroom absurdities and clandestine passions without compromising either.