When her dad gets a job overseas, Konatsu Amano has to leave the Tokyo life she's always known and relocate to a small seaside town to stay with her aunt. The move also means starting a new school surrounded by complete strangers, and it's a lot to handle for a girl who has trouble with change. But on her first day in her new town, Konatsu is instantly drawn to Koyuki, an older girl who is the sole member of the Aquarium Club. Konatsu's introverted tendencies are hard for her to overcome, but maybe she's found something worth coming out of her shell for?

A sudden fever keeps Koyuki from participating at the Aquarium Club open house during the Nanahama High School culture festival. After a successful solo amberjack show, Konatsu stops by to wish Koyuki well and teasingly compares her to the salamander from a short story. Now Koyuki can't stop thinking about how Konatsu once compared herself to the frog from that story. As school obligations keep them apart, Koyuki and Konatsu start to realize just how important they are to each other.