The Internet is messed up - everywhere. And Oz, a mega-site that combines social networking with e-commerce with entertainment and the chance to order pizza, has been corrupted.

It's a World Wide Web catastrophe, but luckily there's a teenage math brainiac named Kenji who may be able to save the day, if only he can get his avatar to face off with the towering cyber-villain Love Machine.

An enjoyably trippy Japanese animated feature from director Mamoru Hosoda, Summer Wars combines real-world drama (school crushes, testy relatives) with virtual-world dramatics. There are scenes in Ueda, the Japanese city where Kenji and his would-be girlfriend, Natsuki, go to visit her family, that have the lovely, painterly quality of a Miyazaki cartoon.

And then there's the virtual landscapes of Oz, a pop-art universe that combines vintage psychedelia with colorful, Takashi Murakami-style iconography. (Oz, in fact, could well be what Mark Zuckerberg has in store for Facebook: a site so essential to people's lives that when it crashes, it throws the entire universe into a state of desperate chaos.)

Although Summer Wars' plot lines are as tricky and multitiered as The Matrix or Inception, the relationships in Hosoda's movie are plain and simple: Boy likes girl, girl tries to pull one over on her parents and grandmother, boy gets caught up in a hacking scandal, long-gone older cousin reappears and sets girl's heart aflutter, uncle brings home cases of squid for dinner . . . OK, maybe it's not that simple.

In a world where just about everyone has a virtual alter ego - lots of them with big, round eyes, fuzzy tails, and cute, pointy ears - it's hard to keep the alternate realities from crashing into one another. Summer Wars is eye-popping anime fun, but it's also a bit of a cautionary tale: Watch out, the movie says, or we may find ourselves lost in a digital Land of Oz, where the wizard is an artificial intelligence spinning out dangerous, and maybe deadly, computer algorithms.EndText

Contact movie critic Steven Rea at 215-854-5629 or srea@phillynews.com. Read his blog, "On Movies Online," at http://www.philly.com/philly/blogs/onmovies/