Kayako Kawamata

Kayako Saeki (nee Kawamata) is the main villain of Ju On The Curse, Ju On The Curse 2, Ju On: The Grudge, Ju On 2, The Grudge, The Grudge 2, The Grudge 3, and Ju On: The Final Curse, and the secondary villain of Ju On: The Beginning of the End, and Sadako vs. Kayako. She is the older sister of Naoko Kawamata, the wife of Takeo Saeki, the mother of Toshio Saeki, the eldest daughter of Mr. Kawamata and Mrs. Kawamata, and also the daughter-in-law of Mr. Saeki and Mrs. Saeki.

Biography
In both original Ju On film series as well as its American adaptation The Grudge series, Kayako is primarily portrayed as a housewife who was slaughtered in cold blood by her husband after he discovered she had feelings for her son's teacher by reading her diary and thinking they had an affair. He later murdered their son Toshio Saeki because he had witnessed his mother's murder as well as his now-uncertain paternity. After her death, she and her son became vengeful spirits as their violent death triggered a horrifying curse revive them as a vengeful ghosts. She killed her husband in revenge, causing him to become an evil spirit as well. This led to them killing anybody that set foot in the house they lived in. The curse would spread after more people were killed and became evil spirits.

Ju-On series
In Ju-On franchise, as revealed in the official novel written by Kei Ohishi, both of Kayako's parents were present albeit highly neglectful, causing Kayako to often feel depressed and lonely. Kayako spent most of her free time with her pet cat named Kuro and was highly anti-social. In the first installment of the Ju-On franchise, Ju-on: The Curse, Kobayashi's wife Manami Kobayashi remarks that she remembers Kayako from high school and that she found her "creepy". Kayako became highly jealous of Manami and even tried to curse her, but failed and eventually gave up. When she attends university, she meets Shunsuke Kobayashi, with whom she falls deeply in love. After the accidental deaths of her parents which didn't seem to faze her, Kayako marries Takeo Saeki, the only person who understands and cares for her, and together, they have a son named Toshio. By now, Kobayashi is Toshio's school teacher, and she falls in love with him again.

She writes of her feelings for him in the journal she kept all her life, in both franchises this ultimately leads to Takeo finding and reading her diary. He becomes obsessed with the idea that Kayako is "secretly" cheating on him with his son's teacher - or worse, Toshio could not be his son, but Kobayashi's. When she gets home that day, he violently attacks her upstairs, pushing her against the wall. Toshio is in his bedroom drawing and hears the noise and, coming outside, watches the violence which is occurring below through the banisters. Kayako tries to run away in fear while Takeo chases her, but he pushes her down. She sprains her ankle, stumbles and falls, and has to go down their house stairs by crawling. After much effort she makes it to the front door, only to find Takeo was slowly walking behind her, watching her pain and misery. He then snaps her neck like a twig to a 90 degree angle and crushes her throat, takes her to their bedroom and puts her in a trash bag. Kayako is still alive, but paralyzed, capable only of her characteristic croaking noise. Takeo stares at her just sitting in a trash bag in the bedroom, then stabs her multiple times (an event that does not occur yet implied in The Grudge). Then, he puts her body in the far corner of the attic, through an attic door in the ceiling of their bedroom closet.

After her death, she becomes an vengeful ghost because of the painful and torturous nature of her death. After that, Takeo kills Toshio (a witness to the murder) by drowning him and his pet cat named Mar in the bathtub. He then runs to Kobayashi's house, killing Manami Kobayashi, Kobayashi's pregnant wife in cold blood without showing any remorse at all, and putting her fetus in a sack. As he flies into a fit of rage on the street, Kayako appears as a vengeful ghost coming out from the garbage dumped nearby, and kills Takeo in vengeance. Some time later, Kayako's corpse is found in the attic; Takeo's on the nearby street (his cause of death unknown to the police, they assume he committed suicide) and Toshio's in a closet.

Since that day, the ghosts of Kayako, Toshio and Takeo kill anybody who steps into the Saeki house (and anywhere the curse is transmitted). The cat, Mar, usually appears to forewarn any intruders of their impending doom. The curse is meant to repeat itself as an endless cycle, so the films feature Kayako crawling down the stairs emitting her famous death rattle, cracking her neck around and covered with blood. Although she is usually heard emitting a croaking sound, Kayako is occasionally heard making a strange, eerie moaning instead - she is even heard speaking to Toshio (off-screen) after her death, albeit briefly, and her appearance to Kobayashi during the first Ju-On film.

Sadako vs. Kayako
Kayako serves as one of two titular main villains and secondary threat in the film, as she is tricked to challenged other vengefull ghost named Sadako Yamamura. Through a rumor, it is explained that Kayako was repeatedly stabbed to death by her husband before he drowned their son, Toshio, and hung himself. Ever since, Kayako's and Toshio's spirits haunt their household, killing anyone who steps foot inside. Suzuka Takagi moves in next door with her parents, where she already experiences supernatural visions of the foreboding house.

The psychic, Keizo Tokiwa, intended on having Kayako battle Sadako and have them destroy each another in order to free their current and future victims from their curses. At the same time, however, after spiriting away four schoolboys, Suzuka believes she sees one of them in the house late at night and goes there to check on him, only to have her parents follow after her as well. After Suzuka's father, Mr. Takagi was taken, Kayako appears, taking Mrs. Takagi's feet before capturing her. Kayako was quickly thwarted off with an essence of Sadako's spirit in order for Keizo, Yuri, and Tamao to save Suzuka.

The following night, Suzuka and Yuri enter the house to inflict both curses on themselves. Yuri having previously watched the cursed video two nights prior, and Suzuka setting up a television and VCR in order to watch it in the house. With this, Kayako and Sadako emerge, and with one in the other's way, they enter a brutal conflict. Initially, Kayako dragged Sadako away, only to quickly be overcome and temporarily destroyed.

As Kayako returned, the conflict between the two spirits temporarily allowed the girls and Keizo to escape the house. They retreated to a well, where Keizo explains that one must sacrifice themselves in order to trap both Sadako and Kayako in the well, to which Yuri volunteers. Just as she jumps into the well, something horrific happened: Kayako accidentally merges with Sadako into mass of flesh, giant eyes, and hair. The mass then falls into the well. The mass and Yuri fuses into Sadakaya/Sayako, all-powerful vengeful ghost that possesses all powers of the vengeful ghosts it composed of.

The Grudge trilogy
In The Grudge trilogy, Kayako Kawamata was born to Nakagawa Kawamata, an exorcist (or itako like they call it in Japan). Kayako's mother, Mrs. Kawamata was specialized in removing evil spirits from people. But she had to leave the spirits somewhere, so she let Kayako eat them, marking her for the rest of her life. Worse, she also lacked fatherly figure in her childhood. Contrary to her Ju-On counterpart, the very curse that ultimately revive her and her son as a vengeful ghosts also caused by accumulation of evil spirits that she forced to feed upon by her mother aside simply later murder by Takeo in cold blood.

Later Kayako attended university where she fell in love with a man named Peter Kirk (Kobayashi's American counterpart). Later she married Takeo Saeki, the only friend she ever had and she gave birth to a son named Toshio Saeki. A few years later Peter Kirk, the man Kayako fell in love with in university was revealed to be Toshio's teacher. Kayako falls in love with him again. But this time she became obsessed with him and followed him everywhere. She wrote her feelings for him in a journal she has been writing in since her childhood. Her husband Takeo Saeki was an extremely jealous man and already becomes mad when Kayako says something good about a man she saw on TV.

One day, he found her journal when Kayako wasn't home and thought Kayako is "secretly" cheating on him and might leave him for Peter (who was already married). And he was so mad that the idea that Toshio is not his biological son, but rather Peter Kirk's. When Kayako came home Takeo attacked her and sprained her ankle. Kayako tried to escape the house by crawling down the stair to the door.

But Takeo grabbed her by her long hair, snapped her neck and crushed her throat, so the only sound she could make is a croaking noise. Toshio was watching the whole murder from the stairs in horror so Takeo killed him too by drowning him and eventually killed Toshio's pet cat Mar. And if that wasn't enough, Kayako became a vengeful ghost because of the evil spirits her mother 'fed' her as a child and later, her violent death. She then killed Takeo by hanging him with her hair, and after that incident Kayako, Takeo, Toshio and Mar haunted the house they lived in and Takeo and Kayako killed anybody who entered; Toshio and Mar, both being victims of the Grudge, tried to warn Takeo and Kayako's victims - usually just before it was too late.