Because of their Hamaji Junior High School closing, Umimura residents Sakishima Hikari, Mukaido Manaka, Hiradaira Chisaki, and Isaki Kaname are transfered to Mihama Junior High on the surface.

Because of Uroko-sama's curse, Manaka ends up with a fish face on her knee. It goes away the next day, but she has some regrets because Tsumugu had said it was pretty. Meanwhile, Hikari gets annoyed that Manaka and Tsumugu are talking and tells him to not concern himself with the people of Umimura.

Hikari finds out that Akari's boyfriend is in fact the father of the girl who had been picking fights with him, Miuna. Miuna asks him to help break the two apart. The next day, they are cooking in class and the Umimura kids are being isolated. Manaka works up the courage and tries to get the surface kids to try the food they made, but is greeted with an unfriendly response. Seeing that, Hikari jumps in...

The students get together in their swimsuits for swimming class. The sea kids are still getting used to school on land, but are starting to get along with the other kids. The teacher mentions that he's going to be timing them today and as the kids groan in response, Hikari and Tsumugu's rivalry fires up.

After school, the classmates get together in the woodshop room for the final stretch of getting the Ojoshi-sama done. After the students finish the Ojoshi-sama, even the teacher gets excited about the feat, and they wonder if it's possible to somehow do an actual Ofunehiki like they used to do with the surface and the sea working together.

Miuna makes a snow sea slug out of the saltflake snow that had fallen on the surface. Meanwhile, Hikari thinks about how his father is doing alone in the sea. In the sea, Uroko-sama had gathered everyone to tell them of the calamity that was about to come.

Kaname suddenly confesses his feelings to Chisaki in front of her parents, and Chisaki doesn't know what to do. Hikari and Manaka do their best to go on with the Ofunehiki, hearing that if the Sea God gets his powers back, the disaster that is to befall their world may be stopped.

Tsumugu dives into the sea after Chisaki. He starts having trouble breathing and is about to lose consciousness, but then suddenly gains Ena. Tsumugu finally catches up to Chisaki and lets her know his feelings while they're in Shioshishio. Chisaki cries and runs away.