The Minor Trio learn about the Healing Chest and decide to investigate. Meanwhile, as Hibiki becomes downhearted after failing an English exam, mysterious musical incidents begin to occur around her. Upon returning to the church, the girls learn that Otokichi and the Crescendo Tone know each other, the latter revealing that the musical incidents were her way of cheering Hibiki up. Just then, the Minor Trio create a Negatone from Hibiki's exam paper, which puts the Cures into an English test, attacking Hibiki for every question she gets wrong. The Crescendo Tone almost gives Hibiki a new power, but it fails, though the Cures do manage to defeat the Negatone.
学校で小テストが行われる日。しかし、響は全く勉強ができていなかった。クレッシェンドトーンにテストを助けてもらおうとするが、それは無理なことだった。そこで響は、ヒーリングチェストの使い道を考える。