Agitator (2001)

thank you - and - fu*k you - brother.

When a young Yakuza torments the customers in a rival crime family's nightclub, it is not long before his dead body is found. Soon, inter-family retaliation follows, resulting in the death for a prominent crime boss. Devastated by this turn of events, the temperamental Kenzaki vows to avenge his boss's death and, as bloody violence ensues, the body count reaches excessive proportions.