On the kotatsu, over at No-sword. What I didn't know was that

[s]ince the Great Importation, kotatsu have been too cozy for their own linguistic good -- they're now used as a mocking, disparaging element in words like kotatsu-byouhou ("kotatsu [military] tactics" -- pure theory, never tested in the real world) and kotatsu-benkei (basically the same thing as an uchi-benkei: someone who is meek and submissive while out in the world, but turns into a Benkei-like tough guy at home).

Which makes Descartes' work both literally and metaphorically kotatsu-philosophy:

I was then in Germany, summoned there by the wars which have not yet concluded. As I was returning to the army from the coronation of the emperor, the onset of winter stopped me in quarters where, not finding any conversation to divert me and, by good fortune, not having any cares or passions to trouble me, I spent the entire day closed up alone in a room heated by a stove, where I had all the leisure to talk to myself about my thoughts.

--René Descartes, Discourse on Method