Manatsu Natsumi, a first-year junior high school student, was born and raised on a small island and has been attending junior high school in the city of Aozora since spring. On the day she moves to Aozora City, Manatsu has a shocking encounter with Laura, a mermaid who is looking for a legendary warrior, Precure.

Manatsu starts attending Aozora Junior High School. She goes with Laura, a mermaid, to look for a new Pretty Cure candidate, but if the students find her she's in big trouble...!

Sango happens to meet Laura, a mermaid, at an aquarium. Sango, who lacks self-confidence and naturally goes along with everyone around her, is touched by Laura's words, "What if you don't believe in your own 'cuteness'?

Manatsu, Sango and Laura meet Ichinose Minori, a second year middle school student who knows a lot about the legends and stories surrounding mermaids. Because of past situations, Minori struggles to take a step forward. But then...

Takizawa Asuka is a third year middle school student with a strong sense of justice. Manatsu and Laura ask her to become a Pretty Cure after she helped them...

The girls have found an empty room and finally formed a club! First up, they got to figure out what their club does, however, their ideas keep getting rejected by the student council president... But then four graduates of Aozora Middle School arrive, looking for something they hid 10 years ago...

Manatsu and the rest of the Tropical Club are out running when they find Kururun, a sea fairy, washed up on the beach. It seems that Kururun has lost an important item for Laura, which was entrusted to her by the Queen of Grand Ocean...

The girls want to make lunch for their busy mothers. That's when Manatsu has an idea to have "making lunch boxes" as their first club activity. Everyone then decides to make a dish based on Kururun.

Manatsu is excited to hear that a movie is being filmed at Aozora Middle School, and wants the Tropical Club to star as extras. But she then happens to come across one of the actresses who is struggling with her new role...

With midterm exams approaching, Manatsu is having trouble studying even though her quiz results were really bad. Then, Manatsu's Motivation Power is stolen by the stronger Zenzen Yaraneeda...

The Tropical Club decides to hold a sand art competition with the other clubs at Aozora Middle School. However, just as the sand arts are about to be finished, it starts to rain. Manatsu tries her best to protect everyone's work but...

The Disciplinary Committee have been going to every club room to see if the rumor about a mermaid being at the school is true. When they suspect the Tropical Club of hiding something, Laura's Mermaid Aqua Pot is confiscated...

During the school's lunchtime broadcast, the topic of mermaids are discussed. But when Manatsu learns that the Broadcasting Club members are frustrated over no one listening to them, she comes up with a plan.

The Tropical Club is getting work experience at a preschool. Laura befriends Wataru, who is reading about bugs by himself. But when a Zenzen Yaraneeda appears, Wataru refuses to run away because he is too worried about a swallowtail butterfly's chrysalis...

When Minori is suddenly sucked into the Mermaid Aqua Pot, Laura dives in to save her. But when they come out of the Mermaid Aqua Pot, they two girls quickly realize they have switched bodies! The duo are very confused but decide to enjoy a life they don't usually get to experience...

With Summer vacation approaching, the Tropical Club members have been getting to know each other better through their club activities. However, Laura has been acting rather strange lately. Manatsu and the others notice this and try to talk to her, but...

Manatsu and her friends are searching for Laura who was captured, when they come across a cruise ship that was turned into a Zenzen Yaraneeda. Meanwhile, Laura escapes the Witch's Mansion, and finds her friends on the cruise ship. That's when a miracle occurs and Laura transforms into Cure La Mer!

Now a human, Laura attends Aozora Middle School. However, she is quickly confused. Then, she is invited to participate in the swim team's trial meeting, and is overjoyed to have the chance to play an active role...

The Tropical Club is participating in a campaign set up by the Newspaper Club to investigate the scary ghost stories and seven wonders of the school. While exploring an old mansion in the mountains behind the school, a doll in the room suddenly starts talking to Manatsu...

The Premium Tropical Melon Bread, a limited version of the snack, is being sold at the school! Manatsu manages to buy one, but when she leaves the Tropical Club room for a moment, it disappears! Minori then takes on the role of a detective, and the Tropical Club come together to hunt down the missing Melon Bread.

It's Summer Vacation, and the Tropical Club has decided to have a Summer Training Camp at Manatsu's birthplace, Minamino Island! After creating an itinerary, the morning of departure arrives with the girls feeling very excited. But then a Zenzen Yaraneeda appears...

It's the first day of the training camp on Minamino Island. The Tropical Club have fun at the secret beach that Manatsu recommended. After being told about the mermaid treasure, the girls go to investigate the cave, when they lose sight of Laura...

The training camp on Minamino Island is coming to an end. Manatsu and her friends participate in the island's festival, the "Minamino Festival," where they throw rocks with their wishes written on them into the sea. But for some reason, Laura is the only one who wants to keep her wish a secret...

The Tropical Club accidentally interrupts a TV crew currently filming Yuriko talking about Aozora Middle School when their banner knocks the crew and Yuriko into the fountain. With the Tropical Club's activities about to be suspended, the TV crew recommends the Student Council and the Tropical Club versus each other in a quiz show...

Sakuragawa-sensei, the homeroom teacher of Class 1-5, looks more nervous than the students before Class Observation Day. To everyone's surprise, her father will also be there to observe the class. Manatsu and the others wonder if he has come to assess Sakuragawa-sensei's ability as a teacher, so Manatsu gets her class together to support their teacher.