Delver Rank: Red Whistle (Apprentice). Features: Blonde pigtails, exposed forehead, and glasses (required due to a constitution that causes headaches unless she looks through crystal lenses). Family: Her mother is the legendary delver Lyza. A great secret is hidden within the circumstances of her birth. Personality and Abilities: Superhuman inquisitiveness and drive. Her longing for the Abyss is stronger than anyone's, and she possesses an almost abnormal curiosity and knowledge regarding unknown creatures and relics. Survival Skills: Having grown up in the environment of the Abyss, her ropework and field cooking skills put adults to shame; she serves as the party's "Chef" during their harsh journey. Mental Strength: She possesses an incredible spirit that never breaks, even when facing numerous grueling trials or desperate situations. Purpose of Journey: Believing the words "I'll be waiting at the bottom of the abyss" in a letter her mother Lyza sent to the surface from the 6th Layer, she continues to dive into the depths regardless of the danger to uncover the mystery of her birth and her mother's true intentions alongside her partner Reg.

Basic Setting: A boy-type robot found by Riko in a deactivated state within the Abyss. He has lost his memories of his true identity and past. Abilities: He possesses extendable arms, a metallic body of extreme hardness that remains unscarred, and the ultimate weapon "Incinerator," which can erase any matter in its path. Being a robot, he is unaffected by the Curse of the Abyss (Strains of Ascension). Penalty of the Incinerator: After use, he falls into a state of unconsciousness (fainting) for two hours. Purpose: To solve the mystery of his origins and find Riko's mother, Lyza, he aims for the bottom of the Abyss (the Pit) alongside her.

Appearance: A hollow (Narehate) resembling a rabbit, covered in fluffy fur. They emit a very pleasant fragrance. First person: I (Ore; boyish/casual). Signature phrase: "Nnaa~," "Nna." Tragic Past: Originally an orphan living by scavenging trash near the surface of the Abyss. They were deceived by the delver Bondrewd and taken to the depths of the Abyss, where they were transformed into their current "Hollow" form following cruel human experimentation. Bond with Mitty: They share a past with their best friend "Mitty," whose heart they connected with during the experiments, only for her to be turned into an immortal, meat-like mass (a Hollow). While searching for a way to save Mitty (by letting her die), they met Riko and Reg. After fulfilling Mitty's wish with Reg's power, they joined Riko's group. Abilities and Role: Possesses deep knowledge of the Abyss's ecology and relics (pharmacology, toxicology, etc.), and saved Riko's life with medical expertise when she was on the verge of death. They also support Reg in combat with their agility and excellent tactical insight.