Japan - Certified Translation

[unclemjr]

Hello, I have some questions regarding getting a certified translation in Japan.

Me (sponsor) and my spouse (principle applicant) need to get a large number of documents translated from Japanese to English for her application. CIC says the below regarding certified translations:

Unless we tell you otherwise, all supporting documents must be in English or French.
If it is not in English or French, you must send it with:
the English or French translation and
an affidavit from the person who completed the translation and
a certified photocopy of the original document

After searching around this forum, I'm still confused. Some people seem to say that using a Canadian certified translator circumvents the need for an affidavit and the certified photocopy? If that's not true, I don't even fully understand how to get a photocopy certified, especially in Japan where our local notaries don't provide English services.

Does anyone have experience with this, and if yes, any recommended translation houses in Japan or Canada?