The Masuzoe-gumi was a Japanese yakuza family founded by Koji Masuzoe as a subsidiary of the Yomei Alliance. The family was one of the largest within the Yomei, with its home turf being the district of Onomichi; the family also included the Hirose-gumi among its subsidiaries. In 2016, the Masuzoe clashed with its subsidiary due to Kazuma Kiryu's interference with Masuzoe's disciplining of Hirose-gumi captain Tsuyoshi Nagumo, and the family responded with a manhunt for Kiryu that only resulted in Kiryu nearly killing Masuzoe as he cowered at the feet of Kanji Koshimizu. Within a few weeks, Masuzoe was exposed as a Saio Triad infiltrator and was murdered by Toru Hirose on orders from Chairman Heizo Iwami to protect the "Secret of Onomichi," and the family may have dissolved following its patriarch's death.