I was first talked into watching this movie. I (unfortunately) had judged it by it's name and thought it to be something really stupid. Boy was I really, really wrong. This is one of those must see anime movies. The animation is good and the plot is perfect. To be honest, I wasn't this freaked out by scream, or even halloween. The basic backstory follows a legend. There's this stuff called Mermaid's flesh. If you eat it, you become immortal. However, if you're not strong enough to stand the flesh, you either die or turn into this hideous monster called a 'lost soul'. The story picks up a bit where it's predecessor, Mermaid forest, left off. Yuna, a 500 year old immortal, and his travelling companion, Mana, are on their way to find work in Japan. That's basically all I can tell you without ruining the awesome plot twists, except that kids really CAN be evil. Definitely recommended.