An AI decides the cure for loneliness is a public serenade in the middle of class, and somehow that's not the embarrassing disaster you expect, it's the moment everything shifts. Shion doesn't understand why humans hide their feelings, so she just burns through that wall with pure, unselfconscious joy, and watching Satomi get dragged into that vulnerability is the real story. The musical numbers aren't interruptions; they're the only honest language this show trusts to say what matters.

Shion arrives at Keibu High School with an infectious smile and athletic grace that quickly wins over her classmates. Secretly she is an artificial intelligence still being tested, meant to pass as an ordinary teenage girl, but she has her own aim: to make the lonely Satomi happy. Shion's methods are unconventional, starting with a song aimed at Satomi right in the middle of class. After learning what Shion really is, Satomi and her engineering-minded childhood friend Touma gradually grow closer to the new student, joined by the popular Gocchan, the determined Aya and the judo club member known as Thunder. Shion's voice and sincerity move them even as her antics leave them baffled, and her efforts on Satomi's behalf soon pull the whole group into serious chaos.