Yakuza Cheats

Yakuza Unlockable: Adventure Review Mode
You must finish the game. Duh.

Yakuza Unlockable: Movie Viewer
Finish the Game.

Yakuza Unlockable: Infinite Heat
You must get S Rank on all 50 missions in the extra battle review mode.

Yakuza Unlockable: Secret Boss Fight
You must do of all the side quests.

Yakuza Unlockable: Battle Mode
Finish the game.

Yakuza Unlockable: Master Fighter
You must achieve S Rank in all 50 missions in the extra battle review mode.

Yakuza Unlockable - Secret Weapon Shop
Be on Chapter 4 of the game and go to Taiheio Street East and you will see a homeless looking man standing by a car about a block north past the Akagyuu Beef Bowl Resturant.

Talk to him and he will tell you he is selling some information. Buy it and he will tell you ask for a certain thing from adult film rental store (the purple store located northwest of the man). Talk to the clerk and request the mentioned movie and will trigger the cutscene to the shop.