Yamaguchi, born Yusuke Yamaguchi in Tokyo, Japan, is currently hospitalized. His brother Shunsuke Yamaguchi, who is currently one half of WWE's Japanese announce team, posted a photo of his brother on Facebook with an update.
"Some of u might have heard but my brother Yusuke, aka Yamaguchi Wally or Yamaguchi San had a stroke," he wrote. "This is a pic from 1am est. Don't know how long he has. Some of his friends from school and Gong Magazine have visited him. Love you brother!!!"
Kaientai got its start in Michinoku Pro Wrestling in Japan in 1994. The stable originally featured Japanese wrestlers Shiryu, Dick Togo and Mens Teioh, and then was later joined by Funaki and Taka Michinoku. Funaki took to Twitter to offer prayers for Yamaguchi.
Kaientai had a short stint in ECW in 1997 as BWO Japan and then debuted in the WWE in 1998 on RAW after WrestleMania 14. The faction infamously feuded with Val Venis, which culminated in a segment that saw Yamaguchi attempt to cut off Venis' genitalia with a sword.