It's the sports rivalry you didn't even know existed, borne out of the last event you'd expect to foster one. No one treats All-Star Celebrity Games with any seriousness, but for Michael Rapaport, a fun event became a chance to shine in 2010 when he won MVP. Then Justin Bieber snatched it all away from him just one year later and nothing was the same.

Fast forward to 2015 and the loss still haunts Michael to this day. Meanwhile—where is Justin Bieber now? He's touring, making more top 10 hits, gracing our cover, and preparing a new album. All while silently laughing at Mike's tribulations.

But that's all about to change. Michael Rapaport invited Complex to shadow him as he trains vigorously for the rematch he's waited damn near half a decade for. Join us along with Michael's son Dean, Justin Bieber, and Scooter Braun as the showdown four years in the making comes to a head in L.A. Will Michael school his pop star nemesis with some Higher Learning? Or will the Biebs press down on the gas pedal to finally shut Michael's old ass up?