Detective Nakagawa: It is said in Japan that when a person dies in extreme sorrow or rage, the emotion remains, becoming a stain upon that place. Death becomes a part of that place, killing everything it touches. Once you have become a part of it, it will never let you go.
Detective Nakagawa: Three years ago, three of my colleagues were investigating what happened in that house. Two died mysteriously. The third was never found.
Kayako Saeki: Croakkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk.
Karen: There is something evil there.
Karen: The whole time I was in that house I felt something was wrong. What happened there?
Answer: Well, in the Japanese original (Ju-On: The Grudge), it shows that Takeo, the father, killed his wife by shoving a knife down her throat or something similar to that. When he was killing her, she tried to scream, except her scream came out all messed up (because the knife hit the vocal chords), which explains the horrible croaking noise. There's no doubt about it that it's the way she was killed in this version.