Hello PUMU!
TNT, the creator of this bag, is a member of the Korean Strida Club.
According to the English parts of this post at the Hong Kong Strida Club forum,
http://www.hkstrida.org/forum/viewtopic.php?f=18&t=3388&p=36875
(Registration and login required)
the group ordering of the bags has ended ~ 2 years ago.
Possibly these bags were never available outside of HK and Korea…
I mean would be possible to ask at the HK or Korean forums directly, and/or the members above.
The faster way to get such a bag will be to ask your wife, mother or grandma, maybe one of them has a sewing machine?
What about creating your own European version?