Aki is growing impatient. Even if she was told to picture the uni as a cash box, instead of sea urchins, she still cannot reach them. Hiroshi visits her at the beach. He shows signs of liking Aki but she does not notice. Somehow she and Yayoi cannot even remember his name. When Hiroshi asks if Aki can fetch him an uni, she says, "I can do it!" She struggles but ends up "catching" a coin instead. Meanwhile, daily life for Natsu has changed significantly now that Haruko and Aki are staying with her. All three help out and take turns doing their tasks: preparing and selling the unidonburi, diving, manning the shop, etc. One dinnertime, Aki says her Dad is a good cook and would usually cook dinner for them in Tokyo. Also Natsu tells Aki that since it's already September, the sea currents have changed and it might be too dangerous for an amateur like Aki. "You can only dive up to 4 pm." Aki is disappointed since it means less time to practice her diving. Next day, Aki as usual fails to catch any uni so she dives once again alone past 4 pm. Even if she was warned not to go past the cove, she goes over there after spotting plenty of uni. A sudden current pulls her to some kelp. Her foot gets entangled with it, preventing her from resurfacing. Natsu and the ama-sans panic but fortunately she is saved by Kumagai Misuzu (Ama, 50 yo). She is fine but Natsu is furious. "You don't listen to your seniors, so I'm banning you from the beach!" Haruko who had arrived defends Aki by arguing with Natsu. Their quarrel becomes heated and personal to the point that they were not really talking about Aki anymore. Aki tries helplessly to stop the two from fighting.
アキ（能年玲奈）は、祖母・夏（宮本信子）、母・春子（小泉今日子）と、３人での生活を始めた。張り切って海女修業に打ち込むが、早くも大きな壁にぶつかっていた。いまだにウニを一匹も取ることができないのだ。秋が近づき、このまま海女漁の季節が終わってしまうことに焦るアキは、夏との約束を破って危険な時間帯に海に潜ってしまう。海の中で、大きな潮の流れにのみこまれて身動きが取れず、アキは絶体絶命の危機に！
