No cheat unlocks Tokyo. Midnight Club: LA Remix (PSP) only contains **Los Angeles** and **Las Vegas**. Tokyo was in Midnight Club 3: DUB Edition (PS2/PSP/Xbox), not the LA Remix.
| Game | Cities |
|---|---|
| Midnight Club 3: DUB Edition | San Diego, Atlanta, Detroit, **Tokyo** |
| Midnight Club: LA / LA Remix | Los Angeles, Las Vegas |
If you want Tokyo, play Midnight Club 3: DUB Edition on PSP/PS2/PC (via emulator).