Michelle got trouble to explain KAGAMIMOTI to a foreigner.
I know your problem when you couldn't do that. I don't know about such traditional at all too.

Don't be discouraged, and let him know it's a common that many japanese do not know about it.
In such case,why dont you make it "joke", like "it's just preserved food" or
" I'm not a scholar, how do I know", and lough it away.
But, you must be cheerful and friendly at that time.

Any way, I think you are lucky to have such a good chance to hear and speak english. You know, ordinary people seldom have oppotunities to hear and speak english. So, do not be too searious to contact with foreigners.

But, I imagin that it is hapuninng on you work, so you must be seriouse. I hope you treat well such opportunities.

Speakinng of the dog, your SUZU is a blind dog ? and she can't hear anythig at all ?.
Because of she is still 5 years old, I feel very sorry the condition you are having. Please take care of him.