3 sun size

3 sun size is the traditional (old) Japanese measurement. It is no longer used in daily life in Japan. It is equivalent to 9 centimeters or 3.5 inches. It is popular as a small box with palm-sized. The 3 sun box was a size never seen before in the history of Japanese puzzle box. so I started making boxes of this size in 2004. The photo shows the structure of 3 sun boxes.