Satoko Houjou hails from Hinamizawa village, emerging as a core member of the after-school club. Her distinctive features include short blonde hair typically secured by a black headband, magenta or purple eyes, and prominent canine teeth. She frequently wears a light green sailor uniform with a yellow scarf, casual denim shorts paired with a pink sleeveless shirt, or a navy blue swimsuit. Later attire encompasses a dark blue middle school sailor uniform and St. Lucia Academy's high school uniform with knee-length socks. Mischievous yet intelligent, Satoko engineers elaborate traps—earning the moniker "Trapmaster"—and demonstrates sharp analytical skills in environmental mapping and behavior prediction. She adopts formal speech patterns with grammatical stumbles, projecting a haughty or bratty exterior. Prone to tears when teased or losing, she occasionally weaponizes vulnerability for sympathy. Underlying emotional fragility stems from abandonment fears, fostering extreme self-reliance and resistance to seeking aid. Her turbulent past involves maternal surname shifts—Hatake, Yoshizawa, Matsuura, Houjou—due to multiple marriages. Satoko and brother Satoshi faced village ostracization over their parents' dam project support. After their parents' 1980 deaths (disputed as either a push during Satoko's paranoid episode or accidental railing collapse), she endured abuse under relatives Teppei and Tamae Houjou. Tamae's murder by Satoshi and his subsequent disappearance left Satoko alone until Rika Furude took her in. Key developments include surviving terminal Hinamizawa Syndrome via experimental drugs in Matsuribayashi-hen, cementing her reliance on Rika. Their bond shatters in Gou/Sotsu when Satoko struggles academically and socially at St. Lucia. Feeling betrayed by Rika's assimilation efforts, she accepts looping powers from Eua, orchestrating repeated tragedies to imprison Rika in Hinamizawa. Embracing a "witch" persona, she manipulates timelines with calculated cruelty, rejects her humanity after killing a reformed Teppei and an alternate self, and engineers mutual deaths across fragments. Relationships pivot her arcs: She views Keiichi Maebara as a brother figure ("Nii-nii") but later assaults him in Tatariakashi-hen to advance schemes. Shion Sonozaki ("Nee-nee") evolves from murderer to ally. Her dynamic with Rika shifts from codependence to violent rivalry, culminating in looping confrontations that nearly break Rika before their Sotsu reconciliation. Alternate timelines depict variations: Saikoroshi-hen's Satoko has a stable family with Satoshi, excelling academically while coldly bullying Rika for perceived manipulation. As an adult in Rei, she marries Kisaku Kimiyoshi, operates the "Smile Store" souvenir shop, and raises daughter Sakiko.