In the year Kanei 17, the man-made island of Dejima, home of many foreigners, has been brutally attacked by a ninja squad sent by the shogunate. At the same time, a mysterious golden dragon has appeared off the coast of Nagasaki. Hearing of all this, the penniless mercenary Gokurakumaru heads off to Nagasaki with his lover Oyuri and assistant Togizo in hopes of striking it rich. But just what are they getting themselves involved in?