JR East will be opening a railway goods shop called General Store Railyard in the west concourse of Omiya Station. At the link below you can find a pdf illustrating some of the items available. Among other goodies, a few must-haves:
JR East pajamas as used on the Hokutosei sleeper service
parts pulled from retired rolling stock
dining car beef curry
Hokutosei spoon and fork set
decals as used inside E233 series cars to indicate car designation/number, decals displaying depot and passenger capacity
towels, key chains, stationery
Kato E651 Swallow Akagi limited edition model
This will open Saturday, March 25, 2017. JR East, please take my money. Courtesy of Railfan News.
http://railf.jp/news/2017/03/09/174500.html