In order to repair Sana's and Nanaka's relationship, Shusuke and Shuri decide to go on a trip to a river to which the five used to go in their youth. Beforehand, Sana accidentally breaks Nanaka's mirror, and Nanaka is appreciative when Sana buys her a new one, but forlorn after learning that Sana bought one for Asami as well. After the group goes to the river, they swim at the spa, where Nanaka is embarrassed at her lackluster swimsuit. As Nanaka is going home with Sana and Aoi, she reveals she made cookies for the group, and the three eat them at Aoi's apartment. There, Sana gives Nanaka a pink stone he found near the river as a gift.