Stacy: Attack of the Schoolgirl Zombies (2001)

Set in a future dystopia where teenaged girls begin dying for no apparent reason -- and often in an elated, chronically happy state of mind. One of these girls, Stacy, is back from the dead, however, and she's ready to gorge herself on human flesh. As more and more teenage-girl zombies begin to feast on the living, the people of Japan brace themselves and try to find a way to end the madness.