We're not well-versed enough in the subtleties of boxing to offer anything more than the most basic analysis of the following video, so we're going to go with just the facts:
1. Justin Bieber and Floyd Mayweather Jr. are friends, or at least acquaintances.
2. Mayweather is training Bieber in the ways of boxing.
3. Bieber throws several punches, and though they are clearly intended as practice punches and are therefore not thrown at full speed, all of them connect.
4. Bieber does not appear to be training Mayweather in the ways of singing or dancing.
That's it. Now you know this information.