What you could probably do is find a stained glass artist here in Japan who can help you out with purchasing the supplies you need.
I think there is one such artist somewhere in Misawa but I am not sure. She used to exhibit during the Patio Festa (- held at the Veedol Dome in Autumn - but I think this festival has been cancelled this year as I have not seen it posted in the Misawa Home Page).
Another option is to ask one of the craft shops in Hachinohe if they know any stained glass artist they can introduce you too.
I did a google search and found one - http://www6.plala.or.jp/nancy/
- scroll down on the left column and click on the "English here" for the translation. Maybe you can send her an email too - she gives lessons at her studio also.
Here is another site: http://www.yumeglass.com/einlish/index.html
Here is also a list of links you can go through - I think it lists all the stained glass artists with websites (many links are broken though)... http://www.studiopao.com/links2.html
(You may need a Japanese language font in your computer.)
Hope this helps even a bit. Good luck.