Japan adopted a new currency and opened a Mint at Osaka (4th August, 1871), that was the former Mint of Hong Kong, and to prove the perfect quality of the coinage, each year a Report was published, giving all the complete information on issues, but also on the quality of the coins, the equipment of the various Departments, the workers (including their diseases). The publication of these Reports wanted to demonstrate the excellence of the new Japanese monetary system, at the moment when the Government wanted to borrow on the main European markets and to transform the Yen in an international currency. The series of Reports gives a complete description of a Mint in the end of the 19th century. It is a unique documentation published in a very specific moment: monetary unification of Japan, creation of a new monetary stock, evolution from a bimetallic to a monometallic system, depreciation of the silver, etc. The publication of the Reports continues the series of volumes on the money issue in Japan during the Meiji period. There is no complete collection of the Reports published during the Meiji period. We will republish all of them (in 4 volumes), adding a new block of documents on this period