Not long after twin brothers Ryuichi and Ryuji were born, they were abandoned by their own parents. They were then adopted by the Yoshie couple, who ran a small shipping company. Sometime later, the Yoshies gave birth to their daughter Misa. Ryuichi and Ryuji enjoyed pleasant days with their adopted parents and younger sister Misa. When Ryuichi and Ryuji were 15-years-old, their parents experienced extremely dark days because of Genpei Kirishima, who ran a competing shipping company. Genpei Kirishima tried to expand his business nationwide at this time and he tried to deprive business of the company owned by the Yoshies. Due to Genpei Kirishima, the Yoshies fell into heavy debt and eventually killed themselves. Ryuichi and Ryuji vowed to get revenge on Genpei Kirishima. 7 years later, Ryuichi has become a new person through plastic surgery and using someone else's identity. He takes part in the criminal world. Meanwhile, Ryuji works for the Ministry of Land, Infrastructure, Transport, and Tourism, to supervise shipping companies.
~~ Adapted from the novel Ryu no Michi by Shirakawa Toru.