YAKUZA

Yakuza Hints & Cheats
Yakuza Unlockables
Unlock Premium Box

Beat the game once on any difficulty.
End Game Unlockables

Upon completing the game you will unlock various new game modes and extras.
Unlockable How to Unlock
Movie Viewer Complete the Game
Battle "Review" Mode Complete the Game
Adventure "Review" Mode Complete the Game
Master Fighter

Get S Rank in all 50 missions in the extra battle review mode (unlocked after beating the game) and you'll unlock this mode that gives you infinite heat gauge during gameplay.
Secret Boss Fight

Complete all the side quests and a secret boss will appear in front of the movie theater. Talk to him to initiate the fight.
Easy Game Mode

To unlock easy mode, keep dying on a certain fight, die a couple of times and keep retrying(5-10) until they ask you "You want to select to easy game mode?"

Also take note that when you select this easy mode you won't be return to normal mode anymore.

Advantages:
Number of enemies will decrease, they only inflict minimal damage and they attack only one at a time