We also received the same letter today and although it was pretty straight forward, trying to figure out how and where to send is really confusing. There is no pertinent information on the vac site or anywhere else that we have been able to find.
We are also in Japan and with the holiday the Tokyo vac office is closed.
I called the Manila Vac office earlier and although I have to verify everything with Tokyo, this is what I have pieced together so far.
First off, this is something new which explains why there isn't much info about it. Manila also verified that it is new.
Send it to the local vac office which is Tokyo for us even though it is being processed in Manila.
There is a charge
it must be paid in exact cash and in the local currency.
According the the vac Japan site, It must be sent by registered cash mail or HAITATSU JIKANTAI *censored word* YUBIN
I believe it is 5,202JPY for Document Transmission for PR service. This is just a guess based on the price Manila gave me. Confirm with Tokyo. Manila would not accept Canadian $ only their local currency.
Include a copy of the emailed request from cic with your pictures but no other documents are needed (according to Manila)
Until I can talk to someone in the Tokyo office, we are all on hold but at least I have a little bit to go on.
Hope this answers some questions. Again, double check everything with Tokyo or your local vac but I think that's they way it's going to work.
Good luck.