What would you do for a great cause? Would you go through three months of grueling boxing training while juggling your day job and climb into the ring in front of hundreds of your friends and coworkers?

That's what 16 amateur fighters did for "Executive Fight Night," a semiannual Vegas-style boxing event designed to be an opportunity for business executives in Tokyo to let off some steam and raise funds for charity.

Participants went through 12 intense weeks with professional trainers to prepare themselves physically and mentally for the event. Organizers said the fighters were chosen based on skill level, weight and availability, from 40 people who tried out.