Although I never saw him in the movies or TV shows, my impression was that he played the tough guy on both sides of the law. In addition, he had a tongue-in-cheek movie franchise between 1968 and 1972 called the "Furyo Bancho"（不良番長...Delinquent Leader）series where he played the leader of a rough-and-tumble biker gang.
Umemiya also released a number of singles between 1962 and 1982 in which one was "Dynamite Rock" from 1970. Sounding more like a particularly epic version of a theme song for a tokusatsu hero series than anything rock-like, "Dynamite Rock" is a proud theme song for the actor as he and his gang ride along the highways and byways of destiny on their choppers. That getup that he dresses up in on the cover looks midway between Marlon Brando's costume on "The Wild Ones" and one of the uniforms sported by one of The Village People. Daisuke Shiga（志賀大介）and Yutaka Shima（島豊） were responsible for words and music respectively.
"Usshisshi Bushi" (Hee Hee Song) is a more twist-happy number on the other side of the "45 that takes the music closer to Group Sounds territory. Created by the same duo from "Dynamite Rock", Umemiya seems to be playing the schemer in this song, snickering all the way as he sees how his luck goes with money and women.
My condolences to the Umemiya family.