Moufu Obake to Kinyoubi no Kaidan

is a Japanese light novel series written by Tsumugu Hashimoto, with illustrations by Yasuda Suzuhito. The series began publication on December 10, 2002 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
Every Friday, her sister becomes a "blanket ghost" at the landing on the stairs. This Friday, when I and my sister and my sister's boyfriend, Wajin, spent time together, was a moment when I could feel the word "family." After losing my father and mother and becoming only sisters, the word family became meaningless. But the stairs on Friday are a blissful place for me. A heart-warming story that tells various events that occur around high school students and dawn.