With a kendo and amateur wrestling background, Yonekawa trained in and debuted in Gran Hamada's Universal Lucha Libre in 1992. He later joined Michinoku Pro Wrestling, where after years in the low card, he became Yone Genjin, a humorous cavemangimmick. He had a comical feud with Wellington Wilkins Jr. before being sent to Consejo Mundial de Lucha Libre to train, which was in storyline explained as Genjin himself swimming his way to Mexico through the Pacific Ocean. Upon his return, now as a more civilized, Spanish-talking version of himself, but his luck did not change, being relegated again to low card comedy matches. In December 1998, Yone Genjin announced his retirement after a head injury. He would be replaced by Tsubo Genjin, a similar character played by Hiroyuki Kotsubo. In December 2001, Yone Genjin made a surprise return to M-Pro as a sporadic wrestler, forming a tag team with Tsubo Genjin. Their alliance ended in November 2002, which was followed by Tsubo defeating Yone in a singles match in order to keep the gimmick. After a one year hiatus, Yonekawa returned in 2003 under the new gimmick of Kesen Numajiro,, an eccentric enka singer. Numajiro became famous for coming to the ring while singing, and he even launched several successful singles thanks to Yonekawa's natural voice skills, the first of which was Umi no Tamashii. In 2005, Numajiro turned heel, allying with the villainous salsa stable Los Salseros Japoneses in an attempt to turn it into a band called "Kesen Numajiro and los Salseros Japoneses." He feuded with another music-themed faction, boy band Sailor Boys, over which had the best music, and they resolved to prove it in a match in which the loser would have to drop their gimmick. With the aid of Minamino, Numajiro defeated one of the Satos and stripped them of their music. Numajiro and Minamino took part in the Futaritabi Tag Team Tournament 2004, where they advanced to the finals, but they were eliminated by Shanao & Kagetora. His alliance with Los Salseros Japoneses lasted until June 2006, when the stable was dissolved. Numajiro turned face again, although he kept briefly teaming up with former salsero Banana Senga, who had similarly became a face. Numajiro went unnoticed until 2008, when he formed a successful tag team with Kinya Oyanagi. On May 3, 2012, however, he faced Ultimo Dragon in a match where he loser would be forced to change his ring name, being predictably defeated. Numajiro then adopted the name of Kesen Numagirolamo, a parody of Girolamo Panzetta, and formed a tag team with Dragon himself. He recovered his name back in April 2014.
