Kuroshio, a 4-star Hydro polearm user from Inazuma, is the boisterous and superstitious Maelstrom Harpooner affiliated with Watatsumi Island. At 19 years old, she has a compact, muscular build resembling a coiled spring and features vibrant deep indigo hair styled in a windswept bob, prominent traditional tattoos, and piercing dark teal eyes. Her combat attire is inspired by traditional pearl diver gear, incorporating elements like a slick white tunic, translucent haori jacket, and red-accented accessories. Kuroshio's combat skills include rapid stabs with her harpoon, a powerful elemental skill that summons a spectral shark, and a burst ability creating a damaging whirlpool. Her personality reflects an aggressive but caring demeanor, using loudness as a defense against supernatural threats, while secretly crafting delicate wooden birds for lost souls at sea. Kuroshio values teamwork and leads with fierce courage, embodying both a formidable warrior and a complex individual haunted by her environment.