Konatsu is about to start a new school in a new town, and she's basically all on her own. Her dad just got a job overseas, and her aunt can only check in from time to time. It's a lot for a shy, reserved girl to handle. But on one of the first days of class, she discovers that the school has an aquarium! The club that runs the aquarium is headed by an older student named Koyuki, and Konatsu is instantly drawn to her. Konatsu's introverted tendencies are hard to overcome, but maybe she's found something worth coming out of her shell for?