Presided over by Patriarch Naoki Katsuya, Osaka Enterprises is one of the Omi Alliance's most powerful families in 2012. Using Katsuya's talent company, Osaka Talents, as a cover, Osaka Enterprises does business on the seedier aspects of the entertainment industry, such as blackmail, prostitution and drug dealing. Osaka Enterprises also operates several waste disposal sites where they bury evidence of their crimes, including people (as demonstrated by Kanai's attempt to crush Kan Ogita in a garbage compactor).
In 2012, Naoki Katsuya uncovered that the dying Seventh Omi Chairman, Tsubasa Kurosawa, was plotting to eliminate several high-ranking members of both the Tojo Clan and the Omi Alliance before his death. Since Katsuya had a longtime disdain for Kurosawa and his scheming ways, he informed his one-time friend, Tojo Patriarch Goro Majima about the Omi Chairman's scheme and warned him to protect himself and Tojo Chairman Daigo Dojima.
On Katsuya's advice, Daigo Dojima went into hiding while negotiating with the Yamagasa Family in Fukuoka and Majima faked his death during negotiations with the Kitakata Family in Sapporo, both hoping to covertly uncover who within the Tojo was collaborating with the Omi Chairman. Before vanishing, Majima sent a letter to his ex-wife, Mirei Park, telling her how to get into contact with him, knowing that this message would reach Katsuya, since he was also close friends with Park.
Unfortunately, the family's captain, Kamon Kanai, also got wind of this letter. Kanai, who was secretly collaborating with Chairman Kurosawa against his boss, broke into Park's offices with Kan Ogita to steal that letter. Both men wound up getting caught in the act by Park, who was then accidentally killed by Ogita to keep her from calling the police. Park's death kicked off a series of events that brought Osaka Enterprises into conflict with Park's protegé, Haruka Sawamura, and her foster father's friend, Shun Akiyama. Due to Haruka and Akiyama's intervention, neither Katsuya nor Kanai were able to obtain the letter and get into contact with Majima.
With no further options to uncover Kurosawa's plan and his collaborators, Katsuya mobilized Osaka Enterprises' troops towards Tokyo, making it look like he planned to take over the city while the Tojo were leaderless in the hopes to force Kurosawa and his cohorts into action. The plan was successful, as Kurosawa, Kanai and Masato Aizawa (Kurosawa's bastard son), proceeded to make attempts on the lives of all the high-ranking yakuza whom Kurosawa had marked for death.
In the ensuing battles, Katsuya, Daigo Dojima and Kazuma Kiryu were critically injured, but all of Kurosawa's targets survived and the Omi Chairman's conspiracy was uncovered. The Tojo Clan, Osaka Enterprises, the Watase Family, the Yamagasa Family and the Kitakata Family all banded together against Kurosawa's men and managed to defeat them, resulting in the arrest of Kurosawa and Kanai, as well as the death of Aizawa.