Yoshino is shocked when she is told to start wearing a bra. Per Saori's suggestion, the class decides to do a gender bender play, in which boys play as girls and vice versa, for the upcoming cultural festival, with Yoshino suggesting that Shuichi write the scenario. The next day, Shuichi stays up late thinking up ideas for the play and ends up in the nurse's office along with Yoshino, whose distaste for wearing a bra helps Shuichi come up with the idea for his script. Later, as Shuichi and Makoto become concerned about when their voices might change due to puberty, they decide to do recordings of them as girls, which annoys Maho, who has a cold, and puts her in an awkward situation when her boyfriend, Riku Seya, drops by for a visit. Meanwhile, the class teacher decides to combine Shuichi's original story with Saori's idea for a modern Romeo and Juliet, so Saori invites Shuichi over to her house to work on the combined script. The next day, Shuichi notices Yoshino wearing a bra.
クラスでは文化祭の準備が始まり、1年3組では多数決の結果、さおりの提案した“男子が女子の役を、女子が男子の役を演じる”ことになる「倒錯劇」が出し物に決定。よしのの勧めで、修一は劇の脚本を書きはじめるが、同じく脚本を書いてきていたさおりと、担任の税所先生の提案で共同脚本作業をすることに。一方、バスケ部の顧問から、ブラジャーをつけてくるように言われたよしのは、自分の身体の変化に戸惑いを隠せずにいた。
