This is a low budget movie done well. A vaccination turns all girls school students and teachers into zombies, but only the swim team is unaffected. The reason turns out to be surprisingly simple.
Aki (Sasa Handa) is a transfer student into an all girls high school. She meets Sayaka who recruits her into the swimming team. Sayaka has rather persuasive method, so she joins the swim team. She soon finds out that the everyone is turning into zombies but for some reason only the swim team is unaffected. They form rebel force of their own to combat the zombies.
There are gratuitous lesbian scenes and nude scenes all over this movie. It's hard to judge if this movie was made to show the naked bodies or tell the story. Maybe it's useless to try and figure out which is which, but one thing this movie doesn't fail is to entertain. The girls are beautiful, and the comedy is superb. There are bit of a gore also, but you can easily tell that it's fake.
IMO this is the best movie Sasa Handa has starred in. It's a unique mixture of sex, gore, and high school girls in a story unlike any other I've seen.
This is an uniquely entertaining movie coming from Japan, and is highly recommended.