To very easily pile and bundle used paper such as newspaper or magazines or other objects to be bundled without complication.

The upper face of the plane quadrangle base is divided to four partitions by two lines connecting the centers of the opposing sides of the base and a assisting protrusion, the upper end part of which is formed in a protruding curved surface, is erected at least by one each at the corners of the base in the opposing two rectangle partitions, centering the intersection of the two lines, and a side wall having an L-shape cross section is erected from the periphery end of the two partitions, and four assisting protrusions are erected each at the four corners of the other two partitions.