Saiko begins having romantic dreams about Kishimoto, a boy in her class. Her friend suggests that Kishimoto has used the "Aristotle Theory" to get Saiko to fall for him - breaking into her room at night and whispering in her ear, to implant his voice into her subconscious. Saiko doesn't believe it until her brother says he heard a boy's voice in her room.
That night in her dream, Kishimoto confesses to her with a ring, but is murdered by a man with a knife who calls himself "Jack the Ripper." When she awakes, she finds an empty jewellery box beside her, and Kishimoto is found disembowelled that day.
Saiko's family starts behaving strangely towards her, constantly drilling holes in her walls and ceiling to spy on her. When her friends will no longer let her stay with them, she decides to live with her aunt. She travels to the town where her aunt lives, but finds that there are no bus or taxi services; forcing her to walk. She soon discovers that the roads are completely blocked by wooden buildings, and all the people in the town wear creepy carnival masks. Eventually she meets a man going the same way as her.
The man explains that the townspeople woke up to find the buildings had mysteriously appeared. When people tried to take them apart, they would reappear good as new. Now there are no streets left, and everything is covered in the buildings. People have to walk through them to get anywhere, even though this means frequently going through others' houses. He and Saiko are interrupted when they come to a house whose owners have blocked the door. The townspeople, furious, break in and violently beat the inhabitants.
Saiko wants to leave the town but feels that she must rescue her aunt first. She frees the couple living in the blockaded house. They tell her the masks are worn to preserve some illusion of privacy and to protect everyone from the strange new inhabitants of the town. Saiko's aunt lives in an area where there are many stabbings, and where the strange people have begun to gather. For her own protection, Saiko puts on a mask that one of the townspeople dropped.
Her aunt is nothing like the person Saiko remembers. Aunt Tamae now walks around naked, doesn't wear a mask, and has peepholes drilled in all the walls and ceilings; she has completely rejected the idea of privacy. She wants Saiko to strip and eventually threatens her with a sharp knife. Saiko runs away but encounters strange creatures peeping through the walls. They have elongated heads and many eyes, with a peephole for each one.
Running outside, she comes across the man she met when she first arrived in town. She realizes from the ring on his finger that he is Jack the Ripper. He confesses to killing Kishimoto and says that Saiko was his originally planned victim, but Kishimoto showed up at the last minute. Jack pulls a knife on Saiko but is suddenly killed by Aunt Tamae behind him. She throws her knife into the river and says that following the river upstream will take Saiko out of town.
Aunt Tamae leaves, ignoring Saiko's pleas to come with her. Saiko is left to navigate the buildings by herself.