Satoko is the only surviving member of the Houjou Family, at the start of the series. Her parents were killed on the night of the Watanagashi Festival, after they fell from a cliff. Her brother is Satoshi Houjou, who a year before the start of the series, "transferred" away, leaving Satoko behind with her abusive uncle. She is friends with Rena, Mion, Rika, and Keichii. She can commonly be found setting up traps for Keichii to fall into, and is initially seen as a trouble maker, however after learning about her past, Keichii sees her in a new light. She eventually sees Keichii as a replacement for Satoshi, going as far as calling him "Nii Nii" from the Japanese word for brother, "Oniisan."