The sumibashira (also called kakubashira; a corner post or pillar that is square or rectangular) in toko is hidden, which is designed as murodoko (an alcove which is completely plastered), and another sumibashira of the wall on the ro (a sunken hearth; a square box installed into the floor of a tea ceremony room to make a charcoal fire) is also hidden by being plastered.
床（とこ）の中は隅柱を隠した室床（むろどこ）とし炉の上の壁も隅の柱を塗り込めて消している。