Seiji Maruyama is a middle-aged yakuza recently released from prison. Known as "Gozuki" (one of the demon generals from Buddhist mythology) he is the power that his oyabun counts on. But there is one thing his aniki is not taking into account: Maruyama is getting old.
You can skip beginning scenes up to 2nd week on your 2nd playthrough, if you have cleared battle tutorial.