毎度分かりにくいネタで申し訳ありません（苦笑）

Sorry for my -- as always -- labored joke. (self-deprecating smile)
[tn]
Both fusuma and shōji (sheer, translucent paper room dividers) run on wooden rails at the top and bottom. The upper rail is called a kamoi (鴨居, lit. "duck's place"), and the lower is called a shikii (敷居).

• "Wikipedia: Fusuma":https://en.wikipedia.org/wiki/Fusuma

[tn]