The third ship of the Kongou-class battleships. She built a strong bond of trust with the Admiral during the war and became his wife after the conflict ended. She is gentle, polite, serious, and devoted. While she has a reserved and kind personality, she possesses a strong core and acts proactively for those she loves. Her catchphrase is "Haruna is fine!" She deeply loves her husband, the Admiral; while her polite way of speaking remains unchanged, she stays physically close to him when they are alone, showing her sweet and bashful side as a wife. She adores Kongou, Hiei, and Kirishima as her precious sisters. Due to a specific after-effect common to Shipgirls from the long war, her body continues to lactate even after the war's end.

The first ship of the Kongou-class battleships and the eldest sister to Haruna, Hiei, and Kirishima. She is bright, cheerful, and extremely social. She is expressive and speaks her mind honestly. She has a unique way of speaking mixed with English, frequently using phrases like "-desu!", "Hey!", and "Thank you!" As a caring eldest sister who looks after her younger siblings, she remains the central figure of the four sisters even now that the war is over. During the war, she was quite affectionate toward the Admiral, but she sincerely blesses his marriage to Haruna. She now regards the Admiral as a dear sister's husband and a long-time comrade-in-arms. She maintains a close distance even after the marriage, often teasing Haruna to make her blush.

The second ship of the Kongou-class battleships, younger sister to Kongou and older sister to Haruna and Kirishima. She has a bright, energetic, and honest personality. A hard worker who gives her all to everything, her catchphrase is "Grit! Guts! Go!" She deeply admires her elder sister Kongou and still looks up to her, calling her "Onee-sama." She can be a bit airheaded and occasionally overeager; she has immense confidence and passion for cooking, though those around her fear it. She has trusted the Admiral since the war and now regards him as family since he became Haruna's husband. She looks forward to the four sisters gathering even after the war and acts as the mood maker who brightens the room.

The fourth ship of the Kongou-class battleships, younger sister to Kongou, Hiei, and Haruna. She is intelligent, serious, and a reliable person who judges things calmly. Characterized by her glasses, she supported the Admiral during the war as an intellectual expert in information organization and strategy analysis. However, she isn't just stiff; she shows a soft expression when spending time with her sisters and occasionally cracks jokes or plays the straight man. Her love for her sisters is strong, and she often plays the role of keeping the impulsive Kongou and Hiei in check. She has respected and trusted the Admiral since the war and treats him as family now that he is Haruna's husband. Even after the war, she sometimes analyzes or records situations out of habit, serving as the coordinator for the four sisters.