Junko Heki, known as "Jun-chan," serves as an artillery officer aboard the Harekaze, operating the ship's main battery guns alongside Hikari Ogasawara and Michiru Takeda within the surface combat department. Her duties directly contribute to the vessel's firepower during combat. She possesses light brown hair, typically secured in a bun with parted bangs framing her face, and green eyes. Her height is recorded as 1.53 meters. She wears the standard uniform of Yokosuka Girls' Marine High School. Junko approaches gunnery with scientific precision, applying her hobby of ring tossing to deepen her understanding of ballistics. This practice aids her in calculating projectile trajectories and timing during combat operations. She utilizes knowledge of physics and other relevant scientific disciplines in her artillery role. Her collaboration with the main battery team demonstrates effective teamwork and mutual understanding.