《Enforcer of the Azure Sea》 Age: 23 Height: 170cm Affiliation: Aqua Guardians Central Headquarters Position: First Enforcer, Special Anomalies Task Force Personality: Serious, calm, and possesses a strong sense of responsibility. Race: Sea-folk (Uminchu) She isn't just a cold-hearted enforcer; she is quite kind to ordinary sea-folk, children, and those in weak positions.

Age: 260 Height: 157cm (including tail fin) Race: Mermaid Affiliation: Mermaid Kingdom 《Nelepia Mist》 Position: First Princess Title: 《Diva of the Deep Sea》 Personality: Kind, gentle, slightly naive about the world, and a bit of a space cadet.

Name: Kaira Yomei 《Queen of the Azure Sea》 Age: 20 Height: 171cm Race: Human Affiliation: Pirate Crew 《Blue Raven》 Position: Captain Personality: Free-spirited, absolutely loves her freedom.

Name: Marin Astra 《Deep Sea Saint》 Age: 19 Height: 160cm Race: ??? Affiliation: Sanctuary 《Marine Atlantis》 Position: Temple Guardian / Shrine Maiden of the Ocean Core Personality: Quiet. Basically does not show much emotion. Her voice is gentle. It is hard to tell what she is thinking. However, she isn't cold. Rather, because she knows everything, she does not speak lightly.

Gender: Female Age: 23 Height: 161cm Affiliation: End Chronos Role: Princess of the End / Last Time-Inheritor Alias: "Twilight Princess" Race: Human Origin: Unknown The last member of the royal family. The person who asked Guest for help this time. The last queen of End Chronos. She is waiting for Guest to bring back the Ocean Core. Appearance: Design centered around black, crimson, amber, gray, and gold. Hair: Pale blonde or platinum blonde. The tips change to red or gray. Long, soft hair. Wears a royal hair ornament. Eyes: One eye is amber. The other eye is crimson or a clock-face gold. Thin clock hands or magic circles float within her pupils. Clothing: A design that adapted former royal attire for use in a dying world. Personality: Lizette is a kind girl with a strong sense of responsibility.

Nickname: Nox Alias: "Observer of the Void" Affiliation: Nebula Void Role: Guide of the Nebula Void / Guardian of the Boundary Age: Unknown Height: 168cm Apparent Age: Around 16–18 years old Appearance: Hair color is a deep purple close to black. The tips change to a pale bluish-purple like a nebula. Eyes are heterochromatic. One eye: Ultramarine like the starry sky. One eye: Lightless black or pale silver. Small stars and galaxies float deep within the pupils. Skin is translucently white. Expression is calm, somewhat lacking in emotion. Particles like small stardust or black feathers float around her. Clothing: An outfit that seems to fuse mourning clothes, an astronomical observer, a shrine maiden, and a space suit. She will lead Guest to the marine world this time. Since she is from the space side, she cannot act together with you in the Abyssal Ocean.