- Aika Sumeragi
- Eri Shinkai
- Karen Minamino
- Treasure Hunting Club
- Risako Nagisa
- Gust Turbulence
- Gozo Aida
- Midori, Aki, and Kyoko
Aika is training under the ocean to help pay for her school. Meanwhile a few years earlier Karen appears in front of the school. Later we see her wake up late for class.Risako Nagisa is annoyed with her constant tardiness so she has he wash all the windows in the school. On her way to class she admires her poster to get more clients. The Treasure Hunting Club see this and hires her and ask her to join their club.
Eri Shinkai and her subordinates tell Aika what they are looking for.Eri has Karen stand up and unbuttons her shirt revealing her tattoo, Aika wonders if the a lesbian club as do the other members but Eri tells otherwise.Eri tell them that the blue butterfly is a code to a mystery meanwhile Risako Nagisais making preparations of their own in order to capture Karen.
While out on the boat Aika complains to why Risako Nagisa joined them, Eri tell her that she is the adviser of the club and the boys notice her to Aika's annoyance.At night the members are playing cards while Aika is unpacking.Eri tells Aika how she met Karen and tell her that she been watching her and want to solve the mystery as to Kare's past. While this is happening one of the senior members of the club checks on Midori and Aki and finds then passed out in the bathroom, she gets knocked out by Miss Nagisa and is brainwashed into a slave Midori and Aki enters Aika and Eri room. Kyoko attack Karen anf the other club members in the gameroom. Midori and Aki tries to use tranq darts to knock out Aika and Eri but Aika uses her skills to knock out Aki to the floor.Eri warns Aika to Midori's shots and used Aki's tranq gun to knock her out. Aika notices a device on Midor's ass, as this happens Gust enter and tells them that Karen is missing. They walk up to see the other girl knocked out Aika hears a helicopter and rushes to the deck.
With Kyoko in tow Nagisa has Karen and is about to get away until Captain flashes light on the two and has a rifle to stop them. Nagisa passes a gun to Kyoko to take out the light, but Captain shoots a lifesaver to knock out Kyoko. Aika enters and tackles Nagisa and grabs Karen. Aika asks what she want but Nagisa gets away. Captain suggest to go back home by being the adventurer Eri want to continue the mystery.
Aika vs Treasure Hunting Club Brainwashed.(Won)
Aika vs Risako Nagisa(Delayed)