Maybe I can help out a bit with the Japanese.
The small label on the box is just some sort of warning list, what you shouldn't do, like "Don't use for anything but Go" or "Don't put it in your mouth" etc.
鳳凰碁石 seems to be the product or company name, something like Phoenix Go Stones. No idea if the company is actually Japanese though, but it seems likely.
竹 is their indicator for the thickness of the stones, in this case 9 mm (from what I could find online).
And they're indeed glass stones, not plastic or anything fancier than glass. I don't know much about Japanese stones, but the brand seems to be pretty popular and reviews suggest they're of decent enough quality. In Japan they seem to go for around 5500-6000 Yen, just as a reference.
I guess they're sufficient for beginners. I'd be happy to have a set, but being a beginner with cheap Korean 30$ 7 mm stones myself, I might not the best person to ask
