The Law of Killing (2005)

Members of the Ryusei Group conspiring to expand their influence into the Kanto region are being murdered one after another. The method? Strangulation with piano wire. The culprit is Sakura Kyosuke, who became a hitman for the rival group, the Jinbukai, to earn money for the medical treatment of his sister, Saori, who has a walking disability. His crimes are both elegant and cruel, making him an indispensable yet troublesome figure for the Jinbukai! However, the Ryusei Group hires former police officer Togawa and orders Sakura's elimination. A fierce battle between two elite assassins now begins. The brilliant, cruel, and tragic story of men who know no other way to live but as hitmen!