In New York, Ash Lynx a boy with an perfect appearance and outstanding fighting power has been leading a street gang at the age of 17. One night, Ash is told the word "Banana Fish" from a man shot by his own subordinate. The word was that Griffin, his brother who was pretty crippled, often mentioned. At the same time, he meets Eiji Okumura, a Japanese boy who came as a photographer's assistant.