Reverse In the central part is the numeral "100", denoting one hundred yen, from which straight lines of varying lengths radiate outward. Above and below are two semicircles abutting the lines. In the upper part, along the curve of the coin's edge, is Japanese text "昭和" (Shōwa), which denotes the reign motto of Emperor Hirohito (Shōwa), the Showa era - "Enlightened Peace". Below is the issue date 1965 - "四十年". The coin's edge features decorative elements in the form of denticles.
Obverse In the central part is a relief image of a grain of flowering rice. Above and below is an inscription in Japanese. The coin's edge features decorative raised denticles.