To make up for missing the beach, Azusa's parents gets everyone tickets to the pool. Ushio decides to keep her distance from Azusa so Norio's secret won't be found out, which annoys Sumika since she's the only one Azusa knows well. Conveniently, Kiyori separates everyone into two groups based on their breast size, putting Sumika with Ushio and Tomoe. Ushio and Tomoe get hit on by some guys, but Sumika scares them off when they show no interest in her figure. Sumika then gets competitive with Tomoe over her swimming ability, but inevitable loses. After recovering on Ushio's lap, she teaches her how to swim. As they do, they are spotted by Azusa, who realises Sumika has feelings for Ushio and wonders if she was just in the way. She does find a little comfort after talking with Tomoe and decides to write a story based on the two.
取りやめになってしまった合宿の代わりにと、プールへ遊びに来た女子部一行とあずさ。必然的にあずさの相手をしなければならない純夏は、汐と過ごす時間が減ることを恐れるが、きよりの発案で純夏・汐・朋絵、きより・みやこ・あずさと二組に分かれて別行動を取ることになる。思いがけず汐との時間が増えて、ひそかに喜ぶ純夏。
一行は、それぞれ大騒ぎを起こしつつも思い思いに楽しむが、あずさはふとした瞬間、汐に泳ぎを教えている純夏を見てしまう。二人の屈託ない表情と、そこに流れる空気から、あずさは彼女たちの特別な関係に気づくのだった。
Para animarlas por perderse el viaje a la playa, los padres de Azusa les dieron a todos boletas para la piscina. Ushio no puede permanecer cerca de Azusa por mantener el secreto de su hermano.
