I'll give a loose translation of what the magazine cover says:
Top title- "This is the world underground fighting."
Text to the right- Something about Vale Tudo in larger text and then literally "Do you know about America's Dog Brothers?"
Lower left-
"No trophies"
"No judges" (I think)
"No referees"
The next part is too small for me to read, but it probably says something about "Being friends at the end of the day." It then goes on to mention the Dog Brothers being in Los Angeles and something about underground fighting.
Damn.... I need a refresher course in reading Japanese!