
Tsubasa Kurosawa (died 2013), alias Kazuhiko Serizawa, was a Japanese yakuza who served as the Seventh Chairman of the Omi Alliance and patriarch of its Kuroha-gumi subsidiary. Kurosawa climbed the ranks of the yakuza through trading his moral scruples for ruthless ambition, and, on discovering in June 2012 that he would soon die of cancer, he plotted to eliminate the leadership of both the Omi and the Tojo-kai to enable his son Masato Aizawa to seize control of both. However, his plan was thwarted by the Omi officers Masaru Watase and Naoki Katsuya, the Tojo leaders Daigo Dojima and Taiga Saejima, the civilians Shun Akiyama and Tatsuo Shinada, and the ex-yakuza Kazuma Kiryu and his daughter Haruka Sawamura, and he was deposed as chairman before dying of cancer.
Biography[]
Tsubasa Kurosawa was born in Kobe, Japan, and he became a member of the Omi Alliance yakuza organization at a young age. Kurosawa started out as a small-time henchman who performed his family's dirty work. He was treated poorly and was once forced to eat feces to atone for a botched job. Tormented by his superiors, and with no friends to support him, Kurosawa developed a ruthless ambition to rise to the top of the yakuza world, killing his aniki and boss in an act of betrayal. By the 1990s, he became the patriarch of the Kobe-based Kuroha-gumi.
Kurosawa's ascent to power was marked by incessant scheming, even against his fellow Omi members. He helped set up the Nagoya-gumi, a quasi-vigilante criminal organization consisting of the citizenry of Nagoya, and had them conspicuously fix the 1997 Nippon Professional Baseball season, resulting in a scandal involving Nagoya Wyverns player Tatsuo Shinada. The ensuing police crackdown on match-fixing in baseball drove both the Omi and the rival Tojo-kai out of Nagoya, enabling Kurosawa's Nagoya-gumi puppets to take control of the city and Kurosawa to establish a lucrative match-fixing racket. He used brutality, treachery, and tenacity to rise to the top, exploiting the weakness of the Omi after the 2006 Tojo-Omi war to seize control from the sixth chairman. Kurosawa appointed the charismatic and fiercely loyal Masaru Watase as his captain, planning on disposing of him eventually. In the wake of the 2010 Tokyo gang war, Kurosawa established cordial relations with the Tojo-kai chairman Daigo Dojima in the interest of enabling both clans to recover from years of warfare and plotting.

Kurosawa in 2012
In June 2012, Kurosawa was diagnosed with terminal lung cancer, causing him to realize that he had nobody to carry on his legacy. This discovery persuaded Kurosawa to reestablish contact with his illegitimate son Masato Aizawa, whom he persuaded to infiltrate the Tojo so that he could give his con control of both the Tojo and Omi. Kurosawa devised an ambitious plan to do so: he would wipe out the leadership of both the Tojo and Omi clans, positioning Aizawa for a takeover. At the same time, the Tojo grew concerned that Kurosawa's three likely successors - Masaru Watase of the Watase-gumi, Naoki Katsuya of Ousaka Enterprises, and Takachi of the Takachi-gumi - were not on friendly terms with their organization, causing Daigo to initiate efforts to establish alliances with smaller yakuza clans across Japan.

Kurosawa in Fukuoka
In December 2012, as the Tojo leadership fanned out across Japan to meet with potential allies, Kurosawa set his plan in motion. He assassinated the Omi officer Takachi and the Tojo officer Azumi in Nagoya, while Goro Majima was reported murdered after meeting with the Kitakata-gumi in Sapporo and Daigo Dojima went missing in Fukuoka. Daigo's disappearance thwarted the first phase of Kurosawa's plan, as his deputy Minoru Aoyama (who was formerly in league with Kurosawa) decided to seize control of the Tojo for himself. Nevertheless, Kurosawa pressed ahead with phase two of his plan: to lure Kazuma Kiryu and Taiga Saejima to Tokyo, where he planned to kill the two men in full view of the Tojo Clan and thus persuade the 30,000-strong clan to surrender to Aizawa. Disguising himself as Osaka Prefectural Police detective "Kazuhiko Serizawa", he met with Kiryu in Fukuoka and gave him information on Daigo's disappearance, leading Kiryu to suspect Aoyama and be lured to Kabukicho by Aizawa's oath brother Yu Morinaga after the latter executed Aoyama before he could reveal the greater conspiracy.

Kurosawa in Sapporo
With Kiryu en route to Kabukicho, Kurosawa traveled to Sapporo, where his minion Shigeki Baba had successfully helped Saejima escape from prison and go into hiding. Kurosawa blackmailed Saejima into helping him find Majima's murderer, claiming that Morinaga was responsible; Saejima headed to Tokyo to conduct his own investigation. In the meantime, Kurosawa discovered from his mole in Katsuya's family, Kamon Kanai, that Majima was still at large and had plans to meet his wife Mirei Park, to whom he had sent a letter detailing his location. Kurosawa ordered Kanai to retrieve the letter by any means necessary, leading to his murder of Park; however, Park had entrusted the letter to Haruka Sawamura, causing Kanai and his boss Katsuya (a friend of Park's, who had helped her leak the letter's existence to draw out the traitors within the Omi) to race to obtain the letter from Haruka. With the help of Park's creditor Shun Akiyama, Haruka managed to escape the Omi and make it to Tokyo, with Katsuya following suit.

Kurosawa shooting Katsuya
By then, Kurosawa had succeeded in drawing Kiryu, Saejima, Katsuya, and even Watase to Tokyo, as Watase - believing that Katsuya intended to conquer Tokyo for himself - raced him to the city. Intent on drawing out the mastermind behind the plot, the four targets staged a fight atop the Kabukicho Hills mall, with Kurosawa arriving to witness their fake "fight to the death." Kurosawa then revealed himself as the traitor and attempted to shoot them from a nearby rooftop, although his poor aim meant that he merely wounded them. He was ambushed by Daigo when the latter came out of hiding, and Daigo offered Kurosawa the option of honorably taking his own life or being executed. Kurosawa delayed Daigo long enough for Kanai to shoot Daigo, enabling Kurosawa to escape.

Kurosawa coughing up blood
Kurosawa then resorted to an all-out invasion of Kabukicho, having the Kuroha-gumi march into the neighborhood while seizing the Millennium Tower and taking Goro Majima hostage. Meanwhile, Baba was sent to the Japan Dome to kill Haruka at her debut concert. While Kiryu and Akiyama fought off Kanai and his army and Tatsuo Shinada rescued Haruka, Kurosawa lured Saejima to the roof of the Millennium Tower, where he forced him to fight Majima to the death, lest he give Baba the order to shoot Haruka. However, Saejima and Majima's fight bought Shinada enough time to defeat Baba, thwarting Kurosawa's plan. Before Kurosawa could have his henchmen shoot Saejima and Majima, Katsuya and Daigo arrived and shot Kurosawa's four henchmen. At that point, Kurosawa's cancer flared up, causing him to cough blood. Kurosawa then revealed the backstory of what he had to do to ensure his legacy lived on, and, while he held out hope that Aizawa could still kill Kiryu and take over the Tojo, Kiryu defeated Aizawa after a hard fight.
The defeated Kurosawa thus lost his position as chairman and succumbed to his illness within a few months.