Hana to Ryuu

The Kazama syndicate had been one of the most powerful and respected yakuza syndicates in Japan. But one day, the leader of the syndicate is brutally murdered and the syndicate is brought down as members of the organization are forced to scatter. Among these are Kazama's young children, including his oldest son Ryuji. They take refuge with their aunt and in time forget the tragedy that befell their family. Years later, when Ryuji has grown into a teenager, he comes home to find his aunt being gang-raped by apparently random thugs. The violence then escalates out of control and leaves everyone in the room dead, except for Ryuji who is covered in blood. Though it's unclear what exactly…