My previous researches seemed to indicate that there was very little or no art glass produced in Japan pre-war in the 20th century (I specify C20 merely because I didn't try to look further back).
Just post-war the Japanese sought industries which could be set up quickly and easily to produce for export. Naturally they resuscitated their pottery and porcelain industries but sometime in the late 40's or very early 50s they begain exporting Art Glass to the USA and possibly elsewhere. Much of it was not very good quality.
Yours does look better quality and reflects porcelain decor - no surprise there so I suspect later than that.
This from Bill Geary may help
First class Japanese art glass is being produced by the Hoya Crystal. The crystal is clear. There is the minimal use of color in a few forms. There was The
Hoya Crystal Museum Gallery at 450
Park Avenue, New York, NY
right behind Gallery Orrefors. It is now closed.
The forms are very exciting and I have included some information in the Schroeder's Antique Price Guide for 2005 and 2006.
There's nothing like yours in their current catalogue at http://www.hoyacrystal.com/
the vast majority of which is clear crystal / cut / and some flashed cut-to-clear.
But here's a sake ? set by Hoya showing a pale aqua blue http://www.d-064.com/images/pickup/pro/hoya_crystal.jpg
Maybe Bill will see this and comment further.
PS Your pics are ok for me as my browser auto re-sizes to fit the page but try www.photobucket.com
where your pics can be re-sized online (use edit ...its VERY easy) even after they have been uploaded.