Okajima Rokuro is quite the unlucky fellow. What seemed to him to be a lucky break at his job, turned out to be the biggest nightmare he would ever experience. While delivering a disk containing his company's secrets, the ship he is on is attacked by a small band of pirates and their ship, the "Black Lagoon." Rokuro soon finds himself abandoned by his company, and with nowhere else to go, he resigns himself to the life of a pirate on the Black Lagoon. While simultaneously dodging bullets from his hotheaded partner Revy, (whose skill with a gun is only rivaled by Rokuro's own skill with words) he learns to adjust to the life of a pirate and joins in on all of the adventure and heavy drinking a pirate's life can offer...