The Nakano-kai (中野会) was a notorious Osaka-based yakuza gang, founded by Taro Nakano (born October 30, 1936, in Oita) in the years after World War 2.
But in July of that year, the Nakano-kai broke spectacularly from its parent in a violent attack that led to the group's disbanding.
In August 1997, four Nakano-kai gunmen walked into the Oriental Hotel in Kobe and assassinated Masaru Takumi, number 2 in the Yamaguchi-gumi and the expected successor to Yoshinori Watanabe.
[1] The Nakano-kai was reportedly angry at Takumi for ordering them to cease hostilities in a local Osaka gang war.
Public outrage over the shooting led to a police crackdown and the arrest of many of the gang's members (however, two of the hotel gunmen are still at large as of 2005).