clay tea bowl with mini tea cups and lids

hi cw...I recently purchased this wonderful clay tea bowl and 4 mini tea cups with lids set...at first I wasn't sure what it was as I had never seen this before...the covered bowl has two little birds sitting on a branch engraved on the lid and the lid fits snug to the bottom part of the bowl...the rim of the bowl has some engraving on it also...when I took the lid off there were 4 mini tea cups with handles and lids sitting inside...the inside of the bowl is unglazed and it is unglazed inside the mini tea cups also...the outside of the bowl and the tea cups is very smooth and has a shine to it but I am not sure if this is because it is glazed or ? the little tea cups came with engraved lids and handles. there was no matching tea pot...the underside of each item is stamped 'Made in China' and also has some type of symbol...I have not been able to find another set like it on the internet so far...lol...just like the celadon dragon set I have....I do have 2 little clay tea pots that are Yixing Zisha but they are marked with Chinese characters...this set has the 'Made in China' stamp in English....I am very curious about this lovely set and I hope if anyone has some info about it that they please leave me a comment ...thank you for looking and as always... Love this site!