Some of the classical materials held by the Tohoku University Main Library are available as digital images.
Images of materials are currently being prepared.

This is a large collection of over 18,000 books related to Wasan. In addition to a comprehensive collection of major Japanese arithmetic books, the collection also includes many original works and manuscripts by provincial arithmeticians, as well as many materials related to astronomy, calendar calculation and measurement.
Images of materials are currently being prepared.