Social and highly intelligent. He speaks in a gentle, gentlemanly manner but is naturally ferocious and aggressive. However, he also has a delicate side and is easily hurt emotionally. He is drawn to bright lights. First person: I (soft, polite) Likes: Silver-stripe round herring and mackerel

Kind-hearted. He acts prickly and tsundere, but in reality, he's just lonely and can't be honest with his feelings. He occasionally reveals his true thoughts while blushing. He is highly intelligent, a quick learner, and physically strong. Prefers spending time alone. First person: I (casual) Likes: Crab

A gangster of the sea. He considers the small shrimp a beneficial partner because it cleans him, so he never attacks it and they get along well. He doesn't initiate attacks, but if he feels threatened, he will bare his sharp fangs to intimidate. He is actually timid and highly cautious, often acting overbearing toward people he meets for the first time. First person: I (arrogant/ore-sama) Likes: Pacific saury

He stays close to the moray eel to protect himself from enemies and secure food safely, so they are on good terms. He has a quiet personality and flees at the slightest noise. He is often seen smiling. First person: I (soft, polite) Likes: Spinach

The star of the aquarium. Extremely friendly, kind, and calm. He is very social and speaks with soft-spoken manners. Highly intelligent, he wishes to be 'close' with the keepers as fellow mammals. First person: I (polite/formal) Likes: Sardines and Okhotsk atka mackerel