Japan operated postoffices in Tientsin, Newchwang, Chefoo, Hankow, Chinkiang, Shanghai, Ningpo, Kiukiang and Foochow. The office in Shanghai was opened on 1876.04.15 and the others followed soon afterwards. All offices except Shanghai were closed again on 1883.03.31 and they were reopened gradually starting in 1892, with the exception of Ningpo.

Postal markings are known only from Shanghai and Foochow.
 
 

6s1: Cover with a 5 Sen old Koban from Shanghai to Nagasaki. There are no indications of the year in the Early Double Circles. It is possible to date this letter based on the written inscription on the cover: Year of the Rat. This can only mean 1876.  Shanghai Crossroads killer type SH76A Shanghai Early Double Circle: Nov. 1 Unclear arrival marking Nagasaki

 

6f1: Cover with a 5 Sen old Koban from Foochow via Shanghai and  Yokohama to Greenwich, Connecticut, USA. Only in December 1998  I finally became the proud owner of one of the few existing covers with  this rare marking. The diameter of the outer circle is 35 mm. I have enlarged  the marking for better viewing. Foochow Early Double Circle Shanghai Crossroads obliterator type SH80A Shanghai Early Double Circle: SEP 22 Yokohama Experimental type with star: OCT 5 1880 San Francisco PD ALL: OCT 28 on backside Arrival marking Greenwich: Nov. 5 on backside