Youki no Yoru: Gekka ni Chigiri Rite Kakuriyo wo Ouka Keru

is a Japanese light novel series written by Soichiro Watase, with illustrations by Kozo. The series began publication on September 10, 2019 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
Spring in the 13th year of the Taisho era. A boy, Yukio Nagisa, meets a beautiful white snake at the Narukawa residence the night before he came to Tokyo.

It is said that she came to ask for help from "Bakenekodo", which sells to youkai, in order to escape from the marriage decided by her father, Yao Yao's big snake, "Jurokuya".

Taken by the owner of the Bakenekodo, Yagiri Yarukawa and Mitama the cat, Yukio boarded the "Tsuneyanomachi" where youkai live, but it was a strange place where the common sense of the human world could not be understood. ―!

Set in Yokohama after the Great Kanto Earthquake, the Taisho Denki romance that spins the relationship between people and youkai.