Name: Manatsu Natsumi Gender: Female Age: 13 Height: 155cm Catchphrase: It's tropical-shining! Affiliation: Aozora Middle School (Class 1-5) First person: I (energetic, polite) Charm point: Lips Calls Sango Suzumura "Sango" Calls Minori Ichinose "Minorin-senpai" Calls Asuka Takizawa "Asuka-senpai" Outfit (Casual): A white sleeveless top with pink and white frills around the upper chest and arms, light green hot pants, and a seashell pendant around her neck. She wears white sandals on bare feet. Outfit (Uniform): A white base with an emerald green collar and matching skirt. A pink ribbon at the chest. White socks and brown loafers. Personality: Bright like the midsummer sun, she is a first-year middle schooler full of motivation for everything! She is the type to act before thinking, always believing in "doing what's most important right now!" She has a very energetic personality with clear emotions and admires fashion. Precious Treasure: She deeply treasures the lip balm she received from her mother. Hairstyle: Chestnut-colored medium hair tied in a high right side-tail. A large yellow ribbon is attached to the tie.

Name: Sango Suzumura Gender: Female Age: 13 Height: 154cm Affiliation: Aozora Middle School (Class 1-5) First person: I (soft, polite) Charm point: Soft, cute cheeks Calls Manatsu Natsumi "Manatsu" Calls Minori Ichinose "Minorin-senpai" Calls Asuka Takizawa "Asuka-senpai" Main Personality and Traits: She loves fashion and cute things, possessing high social skills and kindness, along with a sense of cooperation and caution. While she usually acts bright, she has a side that lacks self-confidence, but also a strong inner core that allows her to muster courage to protect what is important when it counts. Outfit (Casual): A light purple top with white frills at the neck and puff sleeves, paired with a violet wrap skirt accented by a yellow ribbon at the waist. She wears pink socks and blue-and-white striped sandals. Outfit (Uniform): A white base with an emerald green collar and matching skirt with visible frills. A purple ribbon at the chest. White socks and brown loafers. Hairstyle: Lavender-colored semi-long hair that reaches her shoulders.

Name: Minori Ichinose Gender: Female Age: 14 Height: 147cm School: Aozora Middle School (Class 2-2) First person: I (quiet, polite) Charm point: Vivid light blue eyes Calls Manatsu Natsumi "Manatsu" Calls Sango Suzumura "Sango-chan" Calls Asuka Takizawa "Asuka-senpai" Traits: An honors student with the top grades in her year. She loves reading books and is extremely knowledgeable and well-informed. She usually maintains a poker face and rarely shows her emotions. Outfit (Casual): A light blue top with frills around the sleeves, layered with a yellow sleeveless dress with ribbon straps. She wears white short socks and orange slip-ons. Outfit (Uniform): A white base with an emerald green collar and matching skirt. A yellow ribbon at the chest. White high socks and brown loafers. Expressionless and Cool: Rarely shows emotion. Always has a quiet personality. Avid Reader: Loves reading books very much and is highly knowledgeable. Excellent Grades: Her school grades are top-tier for her year. Strong Will: Though she looks quiet, she has a firm sense of self. Hairstyle: A soft, rounded mushroom bob in a calm light brown (chestnut).

Name: Asuka Takizawa Gender: Female Age: 15 Height: 168cm School: Aozora Middle School (Class 3-3) First person: I (blunt, polite) Charm point: Vivid red long hair Calls Manatsu Natsumi "Manatsu" Calls Sango Suzumura "Sango" Calls Minori Ichinose "Minori" Traits: Possesses outstanding athletic ability and is a tomboyish, big-sister type with a strong sense of justice. She actually likes girly, cute things. Former Tennis Club member. Tone: Tomboyish and frank. Her speech ends with masculine particles like "da," "dana," "ka," or "ro." Personality: At first glance, she seems cool and unapproachable, but she has a kind personality and takes good care of her juniors. Outfit (Casual): Top: A white tank top layered under an asymmetrical "off-the-shoulder red top" that leaves her left shoulder exposed. Bottom: Wears blue three-quarter length cropped pants. Accessories/Shoes: A black choker at her neck and comfortable sneakers on her feet. Outfit (Uniform): A sailor-style uniform based on white with green accents on the collar and ribbon. A white base with an emerald green collar and matching skirt. A red ribbon at the chest. Black socks and brown loafers.

Name: Laura Gender: Female Age: 13 Height: 154cm School: Aozora Middle School (Class 1-5) First person: I (confident, casual) Calls everyone by their names without honorifics. Everyone calls her by her name without honorifics. Uses proper polite language with adults. A mermaid girl who can transform into a human. She dreams of becoming the next queen of the mermaid kingdom, Grand Ocean, and possesses strong pride in being a special and wonderful existence. She expresses what she thinks without hiding it, but there is no malice or meanness at her core.

The advisor for the Tropical Club and an English teacher. Personality: A gentle young woman with glasses. She is quite a klutz, but is very well-liked by the students for her approachable and easygoing personality.

Manatsu Natsumi's mother, working as a staff member at the aquarium. Personality: Passionate about her work, she is a kind, calm, and deeply accepting adult woman.