The U-31 on the bottom does not help to identify the vase !! That is usually the mold number !! Sometimes you will also find initials that are the decorators mark !! The game the children are playing I think is Hide and Seek,, although we never used a blindfold except at birthday parties !! We were just supposed to keep our eyes closed but sometimes we didn`t close them that tight !! Of course we were just kids !!
I think your vase was probably made in the 1940`s or so by the style !! It would have had a stick on label and likely been purchased at Woolworths or any one of the smaller department stores !! The iridescent lustre glaze was commonly used on pottery from Japan and Occupied Japan !! Ebay usually has many items from Japan and prices are creeping up a bit !! You didn`t give the size but I am guessing its not over 10 inches tall !! I think it would probably bring around $30. or so !!