Mikiko Amane, frequently called Mikki, is a transfer student whose life of constant school changes makes her avoid forming friendships, viewing them as temporary burdens and fostering initial indifference. Despite a fundamentally kind nature, her energetic, tomboyish, and friendly personality is sometimes overshadowed by naivety and an inability to read social situations, making her appear inconsiderate or rude.

Her defining experience begins upon transferring to a new school where she alone perceives classmate Kaname Nekota as having a cat's head. This uncanny vision sparks an intense, obsessive curiosity, driving her to follow and study him closely. This fixation, ironically, becomes the catalyst for her gradual social integration, leading her to form a squad with Nekota, Haruna Inui, Yukke Kitahara, and Machako Ootsuka. Her initial apathy towards connections evolves into genuine appreciation for these friendships.

Her dynamic with Nekota shifts from one-sided observation to mutual care and emotional support. Though initially annoyed by her attention, Nekota develops feelings for her, culminating in reciprocal confessions and a deepening relationship, marked by moments like a shared kiss in an extra chapter.

Navigating shared experiences—dodgeball matches, cultural festivals, camping trips—and confronting interpersonal conflicts, such as Haruna's initial jealousy, fosters Mikiko's self-awareness, particularly in recognizing romantic feelings she initially struggled to identify. The narrative also grounds her growth in relatable adolescent changes, depicting her physical maturation including her first menstrual period.

Her unique perception of Nekota's cat face symbolizes her emotional journey. By the series' conclusion, she sees his human face, signifying resolution and mutual understanding. The story spans her sixth-grade year through early middle school, charting her evolution from a detached transfer student to an individual capable of sustained relationships and self-acceptance.