Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a Japanese horror movie with some good practical effects, and some bad ones. It's about a young girl named Sayuri (Yachie Matsui) who is returned to her biological parents after living in an orphanage her whole life. When she reunites with her family, she discovers that her father Goro is a biologist who studies venomous species and keeps a basement full of venomous animals including snakes.
In the very first scene we see a mysterious person throw one of the venomous snakes at the household maid, killing her instantly.
We also see a snake drop through a hole in the ceiling of Sayuri's bedroom and land on her bed, causing her to panic and run out and tell the housekeeper.
Later on we see Sayuri open the lid to a bowl of soup to find a snake in the soup. Someone is obviously trying to kill her.
When her father suddenly has to travel to Africa to study a rare species of snake, Sayuri meets her secret sequestered older sister named Tamami (Mayumi Takahashi) who starts to harass her. Sayuri begins to have strange nightmares in which her sister is a snake girl who can throw snakes and kill people or turn the snakes into swords that can kill. Sayuri kills a giant snake in one of the dreams that turns into the dead body of a girl who was trying to help her.
The head nun at the orphanage (Kuniko Miyake) tells a friend of Sayuri's that Tamami is not really her sister. She was accidentally taken home by her parents instead of Sayuri. She tells him that Tamami always liked snakes and played with them, coming to believe she was a snake herself. When she tried to kill a girl with a venomous snake, Tamami was accidentally bitten by the snake herself, leaving her with a disfigured face and forcing her parents to take her out of school and hide her in their attic.
Tamami tells Sayuri that she's a snake, and Sayuri sees that she has scales on her back. She also took a scale she found to her teacher who identifies it as a snake scale, so we are supposed to believe that Tamami is actually part snake, though we don't know if she really changes into a snake girl. We only see her as a snake girl in the nightmares, so it's possible she is only a small part snake due to getting bitten. It's confusing, but it's fantasy so I can't complain too much.
Spoilers Ahead
At the end we discover that Tamami is working with the head housekeeper, who disguises herself as a witch with silver hair, to try to kill Sayuri so Tamami can inherit their money after they kill them, also. That explains the snake killings and attempted killings, but not what Tamami is exactly.
We see a mix of live snakes and snake props in the movie, including an unconvincing puppet monster snake in a dream scene. We see snakes thrown at women several times, which are all prop snakes. The snake girl make-up is kind of silly. She has large fangs sticking out of her mouth and large scale-covered hands with long nails, but otherwise she's a normal woman.
You can watch the whole movie and read a review of it at TheSilverScream.com.