Nishikata, a middle school student, navigates a playful rivalry with classmate Takagi, whose teasing stems from predicting his easily readable reactions. Determined to retaliate against her pranks, his elaborate counter-schemes repeatedly backfire, fueling both frustration and an unacknowledged bond. While fixated on outwitting her—even instituting self-punishing push-ups for each tease, which inadvertently build his physique—he remains oblivious to their mutual romantic tension. Moments like prioritizing walking home with her over friends unwittingly fluster Takagi, yet he dismisses classmates’ speculation about their relationship. Subtle shifts in behavior, such as securing a seat near her after a reshuffle, hint at gradual emotional growth.

As an adult, Nishikata marries Takagi, teaching PE at their alma mater. His muscular frame, honed through years of push-ups, juxtaposes his enduring playful rivalry. Now a father to daughter Chi, he oscillates between recruiting her for lighthearted pranks and modeling responsibility. Though Takagi still anticipates his strategies, his persistence underscores a maturing devotion beneath the comedic stubbornness, evident in his dual roles as dedicated parent and educator.

Childhood flashbacks unveil an indirect arcade-score rivalry predating their meeting, foreshadowing their dynamic. Friends like Nakai and Mano recognize his unspoken feelings, though these relationships remain peripheral to his central rapport with Takagi.

Nishikata’s arc culminates in a manga-confessed summer festival admission, contrasting the anime’s vow to secure Takagi’s happiness. Both versions preserve his core determination, quiet kindness, and incremental recognition of their bond, tracing a path from rivalry to partnership without erasing his earnest, competitive spirit.