Not only that, but as you know some of the characters were based from real life wrestlers too.
You should check it out on Mangafox. At this time, they're reached the Scramble for the Kinniku Throne arc and Kinnikuman Soldier is about to be in trouble... It's been a while, but there's a new group working on finishing the last chapters. I don't know about Nisei, since it's been inconsistent when it comes to scanlation submissions and you can get a little lost.