High-impact slams, chokeholds and daredevil feats of athleticism aren't the usual way to celebrate a 40th birthday, but that's how New Japan Pro-Wrestling (NJPW) will be spending its big day.

The promotion company was founded by square-jawed wrestling legend Antonio Inoki in June 1972. Its signature event has been held annually on Jan. 4 at Tokyo Dome since 1992, but in 2007 they dubbed it "Wrestle Kingdom" after a video game.

For fans of the popular U.S.-based World Wrestling Entertainment (WWE) promotion and its dramatic soap-opera shenanigans, Japanese puroresu (pro-wrestling) might take a little getting used to. The basics are still the same: count-outs, muscleheads, bodyslams and matches that appear somewhat predetermined. The difference comes in the presentation — puroresu takes itself way more seriously.