Thank you for contacting Mearto with your appraisal inquiry.

It is a cute vintage kewpie doll. Such vintage Jesco Kewpie dolls are being offered at auction on a regular basis.
It is in very good condition as you describe in original box and never played with. It is made of vinyl and it is one of the later kewpie dolls. The earlier ones were made of porcelain.
Normally these companies produced dolls in lots of 1000 to 2000 or even more dolls. The market value for such dolls has declined in the past few years. However the fact that you doll is mint in box; in very good condition adds to the value.

The estimate provided is for a well-advertised specialised online toys auction, where I believe the Kewpie doll has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the lovely Kewpie doll. Retail "asking prices" can be higher and vary.

Please let me know if you have any additional questions. I’m happy to help.
Thank you