The only way you actually don't know who the Young Bucks are is if you have been living under a rock for the last 2 years or so, because over that span this tag team has become one of the more controversial teams and one of the best teams in wrestling. Currently, the Bucks are members of the top stable in New Japan Pro-Wrestling known as the Bullet Club and they are also core roster members in PWG out of California. In the past the Bucks have worked for various companies including TNA and ROH as well as numerous others. Like in any other profession if you succeed on your own someone is going to want a piece of your success to try and make their company or team the best. This is the case with the Young Bucks as they are being pursued by various other companies within the US.
Over the past few years the Bucks have been working various ROH events here and there for the company after being away for a few years. But now it seems as though ROH is looking to try and secure the Young Bucks on a more exclusive contract than before. Then you have Lucha Underground who is said to be very interested in securing the Bucks as some new talent to debut for the company in Season 2. The last company with a vested interest in the Bucks is TNA who is said to be making a big play for the team as a way to bring them into the company. Now I am totally unsure what this would mean for their contracts in NJPW if they were to sign a more exclusive contract with either of these companies. I believe that the Bucks would be ok with working for these companies if they still allowed them to work in Japan.
At this point not enough is known about any of these contract talks to know if any of these companies have fallen out of the race or are even close to signing the Bucks. The only thing we do know is whichever company has the Young Bucks is able to say they have one of the most exceptionally gifted teams in wrestling history.