wrapping (something) in a bamboo mat;  wrapping someone in a bamboo mat and throwing them into a river (unofficial Edo-period punishment)
 drainboard;  floor grates;  duckboard;  slatted wood (e.g. used as a base for storing futons inside a cupboard)
 wrapping (something) in a bamboo mat;  wrapping someone in a bamboo mat and throwing them into a river (unofficial Edo-period punishment)