In the streets of New York, Ash Lynx, a 17-year-old Adonis, is a street gang leader with extraordinary fighting skills. One night, a man shot by one of Ash's juniors utters the phrase "banana fish" along with an address. It was a phrase Ash had sometimes heard from his older brother Griffin, who now might as well be dead. Around the same time, he meets Eiji Okumura, a young Japanese man who came to the United States as a photographer's assistant.