Unlock Bruce Buffer:
To unlock Bruce Buffer, win the Gold Belt in UFC Mode. 

Unlock Card Girl A:
To unlock Card Girl A, watch the replay between rounds 100 times. 

Unlock Card Girl B:
Perform all hidden moves of Card Girl A and then select Card Girl A while holding down L1. 

Unlock Dana White:
Complete all challenges with Lorenzo Fertita. Hold L1 on the Fertita picture to choose Dana White. 

Unlock Big John McCarthy:
Complete all challenges with Mario Yamasaki. Hold L1 on the picture of Yamasaki to choose Big John. 

Unlock Lorenzo Fertitta:
Win the Gold Belt in UFC Mode with a created character. 

Unlock Mario Yamasaki:
Win the Gold Belt with a regular character. 

Win Silver Belt:
Finish UFC Mode to win the Silver Belt. 

Win Gold Belt:
Win the Silver Belt then go into UFC Mode and enter your wrestler (with the Silver Belt) in the Free Weight competition. Win the UFC mode to get the Gold Belt. 

Unlock Fighting Styles in Career Mode:
Complete the action shown to unlock each style. 

Nin-Jitsu: Create a Karate fighter and beat Career mode with him.
Karate: Create a Sumo fighter and beat Career mode with him. 
Kung-Fu: Create a Kickboxing fighter and beat Career mode with him. 

Unlock Hidden Moves:
To unlock hidden moves, fulfill the corresponding conditions. 

Move 1: Beat UFC Mode and get Silver Belt
Move 2: Beat UFC Mode in Open Weight and get Gold Belt
Move 3: Beat Arcade Mode
Move 4: Beat Tournament Mode