When Taoka inherited the title of kumichō, it was merely a local family with only a few dozen members. It was Taoka who made Yamaguchi-gumi the world's largest criminal organization. He urged his underlings to have legitimate businesses and allowed them to have their own family, which became a kind of subsidiary family of Yamaguchi-gumi. He also created a structural system in the family. Wakagashira were elected as underbosses to the kumichō and some of powerful members were elected as wakagashira-hosa.
After the death of Taoka, the heir apparentwakagashiraKenichi Yamamoto was serving a prison sentence. He died of liver failure shortly afterward. Fumiko Taoka, Kazuo Taoka's wife, stepped forward to fill the leadership void until a new kumichō could be selected by a council of eight top-level bosses. In 1984, the elders chose Masahisa Takenaka to be the fourth kumichō of Yamaguchi-gumi. One of the other contenders, Hiroshi Yamamoto, broke away from Yamaguchi-gumi with many of its powerful members and more than 3,000 of its soldiers to form the Ichiwa-kai. A bitter rivalry existed between the two groups, which led to an all-out war after the Ichiwa-kai's 1985 assassination of Takenaka and wakahashira Katsumasa Nakayama. During the war, acting-kumichōKazuo Nakanishi and wakagashiraYoshinori Watanabe briefly took the leadership role until 1989.
5th kumichō : Yoshinori Watanabe
The Yama-Ichi War ended with retirement of Hiroshi Yamamoto which was arbitrated by one of the most respected bosses Seijo Inagawa. After that, the clan elected wakagashira Yoshinori Watanabe as 5th kumichō of the organization. Masaru Takumi was elected as wakagashira. He was so powerful and respected within the organization that his influence overshadowed that of kumichō to some extent.
6th kumichō : Shinobu Tsukasa
In 1997, then powerful wakagashira Masaru Takumi was assassinated by underlings of then wakagashira-hosa Taro Nakano. After this assassination, they were unable to choose a new wakagashira for more than eight years. As a result, leadership of the organization became weaker. Finally, in 2005, wakagashira-hosa Shinobu Tsukasa was chosen as new wakagashira and shortly afterward, in August 2005, Tsukasa inherited the position of the 6th kumichō of the Yamaguchi-gumi. Watanabe retired to private life—rather uncommon in yakuza circles, as bosses usually do not retire until their death. Under Tsukasa's leadership, the 6th Yamaguchi-gumi has resumed expansion. Kiyoshi Takayama, kumichō of the Kodo-kai, was elected as wakagashira. They absorbed the Tokyo-based gang Kokusui-kai, thus acquiring lucrative turf in the capital. Tsukasa was imprisoned in December 2005 for illegal gun possession, and was released in April 2011 after serving nearly six years in jail.
Relief support after disasters
Immediately after the Kobe earthquake of 1995, the Yamaguchi-gumi started a large-scale relief effort for the earthquake victims, helping with the distribution of food and supplies. This help was essential to the Kobe population, because official support was inconsistent and chaotic for several days. The Yamaguchi-gumi also provided relief in the wake of the 2011 Tōhoku earthquake and tsunami by opening its offices to the public and by sending supplies to affected areas.
Newsletter
In an effort to boost morale, the Yamaguchi-gumi launched an eight-page newsletter in July, 2013. However, it was only distributed to full members. The publication bridges communication gaps and includes articles on the group's opinion and traditions, as well as columns on angling, with an editorial section written by Kenichi Shinoda.
Yakuza membership has been steadily declining since the 1990s. According to the National Police Agency, the total number of registered gangsters fell 14% between 1991 and 2012, to 78,600. Of those, 34,900 were Yamaguchi-gumi members, a decline of 4% from 2010. Its membership had further declined by 2013, with an estimated 28,000 members, and dropped again to 23,400 members in 2014.
Split in 2015
On August 27, 2015, Japanese police confirmed that powerful factions, including the Kobe-based Yamaken-gumi, the Osaka-based Takumi-gumi, and the Kyoyu-kai, broke away from the Yamaguchi-gumi and formed a new group called the Kobe Yamaguchi-gumi. Prior to the split, the organization consisted of seventy-two factions. This was the first major split since the forming of Ichiwa-Kai more than thirty years ago.