Deciding the best way to stop the PreCure is to separate the bonds of friendship, Siren researches into Hibiki's likes and hobbies. Disguising herself as a transfer student named Sakura, Siren uses her knowledge to strike up a friendship with Hibiki in order to separate her from Kanade, allegedly feeling some signs of friendship herself. However, when Hibiki sprains her ankle during a judo match, Kanade's true friendship shines through. Siren's cover is soon blown and she ends up making a Headband Negatone for the PreCure to fight.
宿題で友達をテーマに作文を書くことになった。響は、何について書くべきかを考える。そして、思い浮かぶのはやはり奏のことだった。そんななか、響はサクラという女の子に出会って、友達になるが...。