I-19, also known as Iku, is a fictional character from the anime series 'Kantai Collection'. She is personified as a submarine girl based on the real-life Imperial Japanese Navy submarine I-19, which was active during World War II. In the series, she is depicted as cheerful and a bit of an airhead, often seen with a playful and carefree attitude. I-19 plays a crucial role as part of the submarine fleet in the game and anime, specializing in stealth attacks and reconnaissance missions. Her unique design and personality make her a fan favorite.