Japan Buyers Guide – Sony

Good news for expat gamers – Playstation 3 games are entirely region free. The console’s menu screens can also be set to English, and many PSN games have an English option. Unfortunately, DVDs and PS1 & PS2 games are region locked (with the occasional exception on PSN).

The Playstation Vita is also region free for games, and has English system menus.
As with the PS3, online content is region locked. It may be possible to download content from other regions by creating different accounts and keeping content for each region on a separate memory card. Check the following link:

http://gaming.stackexchange.com/questions/65269/most-convenient-method-to-switch-between-psn-accounts-to-access-ps-vita-content

As for the Playstation games you can buy in Japan:

Japanese version has English option:

Assassin’s Creed II
Battlefield 1943
Battlefield: Bad Company
Bionic Commando Rearmed
Bioshock 2
Biohazard 5
Blazblue: Calamity Trigger
Bomberman Ultra
Burnout Paradise: The Ultimate Box
Dark Kingdom
Dark Sector
Def Jam Icon
Devil May Cry 4
Eye of Judgement  (although cards are in Japanese, thanks Christopher!)
Far Cry 2
Fight Night Round 3
Gundam: Target in Sight
Killzone 2
Little Big Planet
Lost Planet
Lumines Supernova
Medal of Honour Airbourne
Metal Gear Online
Mobile Suit Gundam: Target in Sight
Ninja Gaiden Sigma
Pixeljunk Eden
Pixeljunk Monsters
Pixeljunk Monsters Encore
Power Smash 3
Prince of Persia
Race Driver Grid
Ratchet and Clank – Quest for Booty
Ratchet and Clank – Tools of Destruction
Resistance Fall of Man
Resistance 2
Ridge Racer 7 (also supports other languages)
Rise from Lair / Lair
Saints Row 2
SOCOM: Navy Seals Confrontation
Sonic the Hedgehog
Soul Calibur 4
Tekken 6
Tomb Raider: Underworld
Uncharted: Drake’s Fortune (Japanese version is partially censored)
Uncharted 2
Unreal Tournament 3
Untold Legends: Dark Kingdom
Virtua Fighter 5
Warhawk
Winning Eleven 2008
Winning Eleven 2009
Wipeout HD
WWE: Legends of Wrestlemania

Japanese version lacks full English:

Afrika
Aquanauts Holiday
Armoured Core: For Answer
Assasin’s Creed
Bioshock
Brain Challenge
Burnout Paradise
Call of Duty 4
Dragon Ball Z
Enchant Arm
Eternal Sonata / Trusty Bell
Everybody’s Golf 5
FIFA 2009
Formula 1 Championship Edition
Genji: Days of the Blade
Guitar Hero 3 (The training is in Japanese, but most of the game is English)
Gundam: Musou
Gran Turismo 5 Prologue
Heavenly Sword
Imabikisou
Intial D: Extreme Stage
Lego Star Wars: The Complete Saga
Mahjong Kakutou Club / Mahjong Fight Club
Mahjong Taikai IV
Metal Gear Solid 4
Mirrors Edge
Miyasato Miyoshi Kyoudai Naizou: Sega Golf Club
Motorstorm
NBA Live 2008
Need for Speed Carbon
Need for Speed Pro Street
Railfan
Record of Agarest War
Rise from Lair (Lair)
Shin Sengoku Musou 5
Shirokishi Monogatari
Star Wars: The Force Unleashed
Stuntman: Ignition
The Elder Scrolls IV: Oblivion
The Godfather (English audio)
The Last Guy

Motorstorm: The Japanese version doesn`t support online battles.

PSP

The PSP is also region free for games.

Games where the Japanese version has an English option:

Final Fantasy Anniversary Edition
Final Fantasy II Anniversary Edition