Honestly think it's likely to be Japanese in origin, although where it was produced i think value is minimal despite being a fine looking tea set.
One of those items that an auctioneer would value at £5-10 but someone out there might happily pay £30-40 for.
Precious metals, known brands and items which are sold regularly are quite easy to value. Others which are more subjective in appearance - well there isn't one valuer out there who hasn't been made to look foolish before.
And if we're happy with owning an antique and it suits your home and personality, then value is almost inconsequential.