The Arakawa-gumi was a subsidiary of the Omi Alliance yakuza organization of Japan. It was founded in the 1980s by Masumi Arakawa after he murdered the boss of the Hikawa-gumi for killing his girlfriend, and Tojo-kai chairman Takashi Nihara welcomed Arakawa and his family into his clan. The Arakawa-gumi became infamous within the Kabukicho district of Tokyo for its violent reprisals against rivals, and Arakawa was nicknamed "Arakawa the Assassin" for his infamy. In 2018, Arakawa's son Masato Arakawa - using the alias "Ryo Aoki" - was elected Governor of Tokyo. The Tojo-kai and Omi Alliance worked together to stop Masato's power grab, and the Arakawa-gumi switched its affiliation to the Omi Alliance as part of the two alliances' plans. In 2019, the Tojo and Omi alliances disbanded, but Yosuke Tendo of the Ryudo-kai assassinated Masumi Arakawa before he could disband his group as well. Jo Sawashiro became the new patriarch, but he soon turned himself over to the police and confessed to his murder of Ryuhei Hoshino of the Seiryu-kai, leading to the Arakawa-gumi's demise.