Having packed some souvenirs, we shipped them back to our hometown (fortunately, this arrangement was decided because the two suitcases were full later in the trip).
The history of mail service in Japan has been long and also very efficient. As long as the recipent address and content are written clearly (i.e. honest and accurate), generally the process can be completed quickly. The two female assistants at the counter can speak simple English.
From Japan to Hong Kong by post, it takes about two weeks; by sea mail, the charges will be much cheaper, but it was told that it takes two to three months; another option is through other international courier companies, which may take three days or less although the charges will be the highest.
The live demo today weight 5.255 KG, together with the paper box, the total charge is 5,150 Yen.