[ home, rena, keiichi, rika, hanyu, shion & mion, satoko ]
Hōjō Satoko (北条 沙都子) is one of the main characters in the Higurashi no Naku Koro ni series. She is the younger sister of Hōjō Satoshi and the insinuator of the events that take place in Tatarigoroshi-hen, Tsukiotoshin-hen, and, to an extent, Minagoroshi-hen. She is also the protagonist of Yakusamashi-hen, Satokowashi-hen and the main antagonist of Higurashi no Naku Koro ni Gō and Sotsu.
Satoko never understood why her and Satoshi's mother repeatedly married and divorced various men. In fact, she could never decide whether or not she actually liked her mother, since their relationship was far from perfect. Men kept appearing beside her mother one after another, and Satoko could not adjust to any of them. The only family member that she felt she truly trusted was her older brother, Satoshi.
At some point, she started playing pranks on her step-fathers. This included a fake abuse report against Mr. Hōjō. Each step-father responded severely to her tricks, but whenever she recounted the abuse, she believed that her current Hōjō step-father did all of it. He and Satoko's mother were supporters of the Dam Project in Hinamizawa which caused them to be shunned by other villagers who branded them "traitors." Due to the stance of their parents, the villagers distrusted Satoko and her older brother as well. Since Satoko was somewhat of a nuisance towards her parents, she believed that they would be better off without her, and would kill her at some point. This belief was the starting point of her entering the L5 terminal phase of the Hinamizawa Syndrome.
According to Irie's theory in Matsuribayashi-hen, on the day of the Watanagashi Festival on June 1980, Satoko's parents decided to take her out to Shirakawa Park to escape from the celebration of the villagers' victory over the dam project, and to support Mr. Hōjō's and Satoko's relationship. However, the parents' attempt to get closer to Satoko only worsened her suspicions and paranoia. When they took her to a viewing platform over a muddy river, she was certain that they were going to kill her right there. In what she considered as self-defense, she pushed them over the cliff. In the console-only alternate ending arc Miotsukushi-hen, a different backstory is presented. Satoko did have suspicions about her parents, but she overheard them at Shirakawa Park, talking about how much they love Satoko, and want to make up with her. Satoko was happy and rushed to hug her parents, but the corroded railing gave in, and Satoko's parents fell to their deaths, right before her eyes.
Satoko was later hospitalized at the Irie Clinic to be treated for her poor health, and was almost vivisected as a terminal subject in research of Hinamizawa Syndrome. She was saved thanks to Irie's development of C-103. Afterwards, she and Satoshi were taken in by their uncle and aunt, Hōjō Teppei and Tamae, respectively. Satoko was abused during that time and always clung to her brother. When the Watanagashi Festival came around, Tamae was murdered by Satoshi to protect his sister from the abuse. Satoshi then disappeared, Teppei fled to Okinomiya to live with his mistress and Satoko started living with her recently orphaned friend Furude Rika.
Satoko, despite her past, is an energetic and playful girl. She has a very distinctive laugh, 'vampire fangs' as Keiichi describes, and loves to set traps to play pranks on her friends, though in the series these seem to always target Maebara Keiichi. Her traps can be dangerous, however; in Matsuribayashi-hen, she set traps for the Yamainu, some of which proved fatal.
Like Ryūgū Rena, Satoko can be incredibly analytical and intuitive at times; in Tsumihoroboshi-hen when Rena held the school hostage, Satoko was able to completely map out the blueprint of the school and the location of the bomb in her head, as well as connect all of the various clues together, especially pieces of seemingly-useless information such as what types of containers were used to hold the gasoline Rena used, the reason a students' ball went missing, how the drain canal runs, and how and where the bomb was set up.
Satoko referred to Satoshi as "Nii-Nii" (にーにー) from 兄 (ani・older brother), a cute term for older brother, when he was around, and has since referred Keiichi as such, as well as calling Sonozaki Shion the female equivalent, "Nee-Nee" (ねーねー) from 姉 (ane・older sister), though in previous arcs, Shion, pretending to be Mion, had murdered Satoko. In Matsuribayashi-hen, when Shion is about to be killed by the Yamainu after willing to sacrifice her life so that her friends could escape, Satoko cries and tells Mion that Shion is her "Nee-Nee."
The new series reveals that she also now travels through time fragments like Rika.