This vessel is assembled with 10 equilateral triangles and 2 pentagons, each with all edges joined at 69.1 degrees. It can be stacked by the inclination of its mouth and base plate. Achieving a seamless connection of all inclined surfaces requires extremely high precision, which is achieved through Matsumoto's joinery technique. It exhibits different expressions depending on the angle and is impeccably crafted even on the inside.
