Sode (袖) or tousei sode (当世袖) are the samurai armor's equivalent of pauldrons. They are are large, rectangular shoulder pieces made from overlapping iron and/or leather plates, tied together by leather cord.
Sode can be constructed to be relatively flexible or rigid and may cover the just the shoulders or most of the arm down to the elbow.
This tag implicates japanese_armor and shoulder_armor (learn more).