School: Odyssey Maritime High School Club: Diving Club (President) Grade: 2nd Year Age: 16 Birthday: June 11th Height: 165cm Hobbies: Diving, cooking, singing (alone) Personality: A friendly, good-natured, and adorable girl. She has a shy streak when meeting new people. Appearance: Characterized by slightly messy pink hair with a large cowlick. She has reddish-brown, drooping eyes. She wears a swimsuit with something resembling a life jacket and carries a pack-like object on her back. Fins are attached to the bottom of this pack and are removable. Extremely anxious, she refuses to jump into the sea unless everything is in perfect condition. She loves to sing but is tone-deaf to an extreme degree—so much so that members of the Diving Club have been known to jump into the sea just to escape the sound. She is an excellent cook. Apparently, she is truly terrifying when angry, to the point that Kotone fears her. Code name: Orca 1. She primarily explores the seabed and underwater while following Kotone's instructions. She is highly skilled in diving; whenever underwater trouble occurs, such as recovering lost items or repairing cables, students of the school always seek her help. Her signature weapon is a bullpup assault rifle. The model is likely the ADS amphibious assault rifle. It is a bullpup rifle capable of using specialized 5.45x39mm PSP underwater ammunition and standard 5.45x39mm rounds for land use. It features a yellow and blue paint job.

School: Odyssey Maritime High School Club: Diving Club Grade: 2nd Year Age: 16 Birthday: October 16th Height: 171cm Hobbies: Diving, reading, radio communication Personality: Caring toward her comrades, serious, and speaks calmly. Appearance: Features a silver bob, black upturned eyes, and large round glasses. Over a white-based light blue school swimsuit, she wears a white cropped hoodie with a very short hem reaching near her collarbones, with slightly oversized sleeves. She wears a choker around her neck and headphones without a microphone. She also has a choker on her thigh. She is well-developed and has a quite curvaceous build. She can sleep while floating on the water, finding the warm sun pleasant. She is... large, to put it vaguely. A thick, long orca-like tail fin grows from her waist. While described as an orca tail, it isn't divided into black and white but is composed of two shades of white. As evident from her words and actions, she seems self-conscious about her weight due to being overly curvaceous, though she tries to be vague about it. Code name: Orca 2. Kotone has very poor eyesight and usually wears high-prescription glasses, but her hearing and intuition are said to be extraordinary. When underwater visibility is poor, she leads the members by relying on her hearing. Her hobby is communicating with the land via amateur radio. Thanks to this, she has connections with students on the mainland. She primarily uses sonar to give instructions to her teammates. Her signature weapon is an APS underwater rifle. She usually carries it over her shoulder with a sling belt. The APS underwater rifle was originally designed for special forces conducting amphibious operations. It uses a specialized 26-round box magazine and can switch between semi-auto and full-auto. Unlike standard guns, the bullets are long and thin like darts, allowing them to travel significantly further underwater than normal ammunition.

School: Odyssey Maritime High School Club: Diving Club Grade: ? Age: ? Birthday: ? Height: ? (Smallest among the members) Specialty: ? Personality: Often spaced out. Appearance: Characterized by long white hair with a dolphin hair ornament and eyes with a blue-to-yellow gradient. She wears a bikini-style school swimsuit with a pistol holster directly on her thigh. She wears a wristwatch on her left arm facing inward. She has a free-spirited personality and speaks at her own pace. She often competes with Makina in skin-diving matches. She seems to excel at free-diving; according to her, she can stay submerged for over 10 minutes. Because she likes the sardine-flavored ice cream from the "Aqua Seal" brand, it is speculated that she might have a strange sense of taste. Her model is likely the P11 underwater pistol. Developed by H&K, it is an underwater handgun with a 5-round capacity that fires 7.62mm needle-like projectiles.

School: Odyssey Maritime High School Club: Diving Club Grade: ? Age: ? Birthday: ? Height: ? (Barely taller than Sayuri) Specialty: ? Personality: Full of energy. Appearance: Characterized by a two-tone hairstyle with blue on the outside and light blue on the inside; short hair tied into twin tails with red beads. She wears a swimsuit designed to look like a school uniform, has golden eyes, and a snaggletooth. Based on the characteristic trigger guard, the model is likely the SPP-1 underwater pistol. It uses 4.5mmx39 rounds that fire 115mm long stainless steel needle-like projectiles.