All Night Long: Initial O(2003)

Original title: オールナイトロング　イニシャルＯ

When a young woman witnesses a suicide she is so overwhelmed with sexual excitement that she masturbates, unaware that she is being observed by a strange man. Later he invites her home where she is wined and dined. Soon she wakes up to find herself locked in a cage. Of course their twisted and sadomasochistic relationship will end in a sadistically explicit bloodbath.