This article is about the terminology. You may be looking for the episode of the same name, Gasaraki Episode 15.

Shikimi (敷居, Threshold) is the term that originally applied to the doorsill or a guiding wood rail for the sliding doors and windows common in Japanese architecture. Since a doorsill acts as a dividing line that separates space, the term was also applied to ceremonial areas, segregated from the mundane world, where special properties were thought to be present.[1]