And PlatinumGames and Sega are both Japanese companies.
Sega doesn't even plan to show the game at next week's Tokyo Game Show, according to MTV Multiplayer. In fact, "any Japanese release will be evaluated after MadWorld is released here."
The plan is undoubtedly in response to a recent spate of Japanese bannings for violence, the most recent being EA Redwood Shores' Dead Space. But the other usual suspects in censorship cases--Germany and Australia--are being treated the same way. "[The German and Australian] markets could see MadWorld, but it's not part of Sega's strategy right now," reads MTV's report.
MadWorld is violent enough to make headlines at Shacknews for that alone. As such, Sega's even concerned about the game's release in the land that inspired Grand Theft Auto 4. "Sega is working closely with the Entertainment Software Ratings Board to ensure the game receives just an M rating ... The ESRB receives new builds on a regular basis and Sega notes their feedback. Sega ... isn't looking to surprise them."