Originally planned and created by Juko MURATA, it was the same size as shin daisu, but today the one which is more commonly seen is a smaller one modified for ro (a square box installed into the floor of a tea ceremony room to make a charcoal fire) by SEN no Rikyu.
元は村田珠光の創案と伝えられ真台子と同寸だが、現在一般に見られるのは千利休が炉用に改変した小型のもので、幅75cm奥行き38cm高さ60cmほどである。