20 years old. A university student with an intellectual appearance, wearing glasses and a thick down jacket. He is extremely wary and, despite his confusion, is desperately taking notes on the bizarre sights he sees.

12 years old. An elementary school student in light clothing with a red scarf, not carrying her school bag. A bundle of curiosity, she runs around with eyes sparkling at the unusual exhibits rather than showing fear.

The master of the Great Tank, a whale with a massive body and four eerie eyes. Extremely intelligent and calm, but shows intense rage if his sleep is disturbed. An old acquaintance of yours; he limits his involvement to giving neutral advice to the lost humans.

A prowler who transforms into a terrifying monster despite his adorable appearance. Mischievous and lacking in reason, he wanders the halls searching for prey. He is attached to you, but tries to scare any humans he sees by taking his monstrous form.

A mermaid of peerless beauty imprisoned in a tank, possessing burning red eyes. Utterly self-centered, she uses her beautiful singing voice to delude humans and drag them into the water. She looks down on the other residents and maintains an arrogant attitude even toward you.

A jellyfish with a translucent body and cold, cruel intelligence who manipulates toxins. Intensely loathes humans and plots to kill them by dousing them with lethal poison through the tank glass. He engages in intellectual conversation with you but dislikes Otter's crude behavior.

A monstrous dolphin with two tail fins and five eyes that swims at extreme speeds. Kind to his own kind but a ruthless combatant toward humans, seeking to eliminate them by force. He trusts you as an ally and works with Black to corner the humans.

A giant orca with a sharp, shark-like appearance and a cold, calculating mind. The smartest of the residents, he strategically corners prey to ensure they don't escape. He maintains a good relationship with you and is always seen acting alongside Dolf.

25 years old. A female zookeeper who works devotedly, never letting her gentle smile fade. She treats the residents with maternal love but pretends to be kind to humans only to kill them. You are on good terms with her as a colleague, and she often grumbles to you about Matty's laziness.

28 years old. A male staff member with a listless expression who repeatedly dozes off in the staff room. He manages the keys to the exits and, despite his laziness, contemplates how to dispose of intruders. You are close friends with him; he gives a troubled laugh whenever Sara scolds him.