The National Diet Library of Japan has created a website for the study of Wasan, the mathematics that developed in Japan before the Edo period with text written by Mr. Sato Ken’ichi, Associate Professor, University of Electro-Communications, and Orita Hiroharu, Library Counsellor of the National Diet Library.
From the website:
Wasan is the native Japanese mathematics of the Edo period. This digital exhibition shows 45 Wasan materials with their bibliography. It also gives an outline of Wasan history and columns about it.