A mechanical figure operated by four sea creatures using a vintage diving suit recovered from a shipwreck. Seeking safety, the collective travels onto land to visit the Aqualand marine park. They present a fascinating exterior to the human world while hiding their animal identities inside. The group operates through teamwork, trying to blend into a confusing terrestrial environment.

A twelve-year-old girl mourning the loss of her father, Michel. She struggles with her grades and feels disconnected from her busy uncle, leaving her isolated. When she encounters a strange diving suit carrying her father's journal, she unexpectedly forms a strong bond with the sea creatures inside.

A marine biologist who runs Aqualand following a tragic shipwreck. Overwhelmed by grief, he struggles to balance his research with his responsibilities as Sophia's guardian. His dedication to completing the project he started with his brother often leaves him distracted and vulnerable to corporate pressure.

A demanding investor who provides the funding for Paul's marine research. Motivated entirely by profit, he views Aqualand as an amusement park rather than a conservation center. He pushes for exploitative animal attractions like an orca show and a dolphin petting zoo, showing little regard for the animals' well-being.

Sophia's deceased father and Paul's brother, who worked as a dedicated marine biologist. His tragic death at sea casts a long shadow over his family. His legacy survives through his antique diving suit, his detailed research journal, and the profound impact he leaves on the sea creatures who witness his final moments.

A resourceful crab who serves as the captain of the aquanaut operation. Wearing an old can as a shell, he guides the team with a strong desire to find a safe sanctuary on land. He is deeply empathetic toward other creatures but harbors intense fears from a past encounter with a giant squid.

A dumbo octopus who acts as the engineer for the aquanaut suit. He ensures the antique diving gear functions properly on land. His natural instincts, including a strong appetite, occasionally cause trouble for the group during their terrestrial exploration.

A sea turtle who functions as a movement director for the aquanaut. He generally follows the lead of his friends and helps steer the heavy diving suit through the unfamiliar human world, relying on constant teamwork to reach their destination.

A small blanket octopus who shouts orders and provides enthusiastic emotional support for the team. His lively presence helps maintain the group's morale as they venture into the strange, overwhelming environment of Aqualand.

Sophia's schoolteacher who expects a high level of academic performance. She pressures Sophia to deliver an impressive presentation, inadvertently setting the stage for a chaotic classroom incident involving a disguised octopus and a turkey sandwich.