Good Costuming Geek!
I was very good today when buying a kosode (pretty pink fabric with floral motif, not at all obnoxious like the pink uchikake from hell) and refrained from giving a lecture on obi when asked if I needed one. I simply said, "Not particularly." The merchant decided that I needed one anyway, so we picked an obi from the bag.
The Japanese clothing I usually wear is from the Kamakura period. The primary outfit consists of white kosode tucked into red hakama - the waistband of the hakama acts as an obi for the under-kosode (what most of us would call kimonos). Day-to-day clothing for noble women consisted of that outfit, and other pieces were worn unbelted (very little layers, because clothing in the period was a direct response to the decadence of the Heian era, a return to simpler ways). I was planning on wearing this kosode over that for court without an obi, just like it was an uchikake. Now I can wear it for later periods, I suppose, since the obi does show up once the hakama goes away.
I just love wearing hakama, though. The legs get so billowy.
Ah, geeky costuming love. Perhaps this obsessions explains suspenders and boots...