I would call this a Japanese lustre ware teapot (though it is hard to tell from the photo whether there is a lustre finish.) If you google Japanese lustre teapot or look in eBay you will see many of a similar shape. Most would have had a printed Made in Japan mark. (Better quality ones would have had factory marks - like Kutani, Noritake.) Probably once part of a full tea set - sugar, creamer, plates. Zillions of it made for export 1930s 1940s even later. Looks like transfer decoration with some hand painting. As a single piece with what looks like some damage to the floral pattern it could be difficult to sell IMO.
