Yoshinori Watanabe was kumicho (Godfather) of the Yamaken-gumi from 1982 to 1989 before becoming kumicho of the Yamaguchi-gumi.[2] Watanabe retired from that post in July 2005, but the Yamaken-gumi remains largely loyal to him. Many of its members were upset that the sixth Yamaguchi don was not chosen from their ranks, instead, the Nagoya-based Kenichi Shinoda was chosen.
In 2015, the Yamaken-gumi, along with several other organisations, withdrew from the Yamaguchi-gumi and formed the Kobe Yamaguchi-gumi. From 2015 to 2020, it was under the umbrella of the Kobe Yamaguchi-gumi.[3] In August 2020, Koji Nakata, the head of the Yamaken-gumi, declared that the Yamaken-gumi had become independent of the Kobe Yamaguchi-gumi.[4]
On 16 September 2021, the Yamaguchi-gumi announced that it will be welcoming back Yamaken-gumi members who had disunited from them in 2015. As a result, the Yamaken-gumi once again became the umbrella organisation of the Yamaguchi-gumi.[5][6]
Before the split, the Yamaken-gumi was estimated to have between 3,000 and 7,000 members. Following the split the number dropped to around 800.[7]
