An honest and cheerful high school girl who works as an aquarist for Gama Gama Aquarium, a small aquarium in Okinawa. She’s very passionate about the aquarium and uses a strict professional tone when dealing with matters that involve the animals. Kukuru has no interest in keeping up with the latest fashion trends like other girls her age. She’s struggling to rebuild the Gama Gama Aquarium, which is on the verge of closing.

A former idol who has given up on her dream. While traveling back home to her parents’ house from Tokyo, she comes across a sightseeing poster. Piquing her interest, she decides to make a pit stop in Okinawa and ends up meeting Kukuru. She’s a serious girl who isn’t a stranger to hard work. She’s good at picking up on others’ feelings, so is well-liked, but because of that, she has a hard time expressing her own feelings.

Kukuru’s classmate and friend from elementary school. Her mom runs a restaurant called Kame and Tsukimi helps out by waiting on tables. Her friends never miss a chance to meet up there. Her nickname is Udon-chan, a play on words off of her first name Tsukimi (Tsukimi Udon is a type of noodle dish). She’s carefree and always up for anything, but is also good at looking after others and is loved by everyone.

A civil servant who works for the town’s sightseeing association. She sometimes helps out at the aquarium and is a reliable person who always goes around and offers support to those in need. Kukuru and her friends call her their “adult” friend.

Kukuru’s classmate and childhood friend. He gets up early—even before dawn—to help out his father who is a fisherman. Whatever fish he catches himself, he gives to the Misakino family. He knows Kukuru better than anyone else and during summer vacation he volunteers to help her at the Gama Gama Aquarium.

An aquarist who works at the Gama Gama Aquarium. He’s a little rough-around-the-edges and looks unmotivated to do anything, but he is good at his job. He isn’t good with women his own age and avoids making eye contact, even when talking to them. He has to work long shifts at the aquarium because there aren’t enough aquarists, so he always feels tired. He loves the homemade plum wine that Kukuru’s grandmother makes.

Kukuru’s grandfather and owner of the Gama Gama Aquarium. He leaves the aquarium in Kururu’s hands during summer vacation while he goes out on “a very important mission” for the sake of the aquarium. He’s a very kind and gentle man.