The outfit is unlocked by finishing in first place in a ranked Terror is Reality Multiplayer match.
Once unlocked it can be worn by going in the restroom in the safehouse and equipping it from the locker on the left.
In Dead Rising 2: Off the Record ,the champions jacket can be found in a Terror is Reality stall in the fortune city arena. Once taken it will become unlocked and can be worn by going to the safehouse restroom and equipping it from the locker.
This jacket gives no special advantages what so ever.
When playing Co-op with somebody.Your co-op buddy will be wearing a orange version of this as the default costume.The yellow parts will be orange instead of yellow and the grey parts will be all black.
There is no way to wear the alternate version of this jacket outside of Co-op.
It sometimes takes more than one. From 1 to 20.