jr east cover for night train

i have a plan to Japan next febuary,i will try to use night train.i want to know JR east cover for seat at night train (i not use couchettes and beds),my route is ueno-akita by Ltd exp akebuno .if anyone know please tell me .thank you very much

Here's what was on JR's website.

The JR EAST PASS is valid for travel on all of the 72 railway lines of JR EAST: limited express trains(except private compartments or berths), including Shinkansen super express trains; express trains(except berths, etc.); local trains (except "Liner"/"Home Liner").

It seems like you can take any train in the network, but it might not cover any surcharges or extra charges.

You can use for free the so called "Goron to shito" compartments on the Akebono night train, as explained on the following page:
http://www.japan-guide.com/e/e2356.html#4

Advance reservations are mandatory.

I've tried to see if "goron to shito" seats are available on the Akebono on the JR Cyberstation website at http://www.jr.cyberstation.ne.jp/vacancy/Vacancy.html.

However, it only shows the availability of the "B" class sleepers. Does this mean that "goron to shito" seats are no longer available for sale?

The jr.cyberstation.ne.jp@website does not always provide complete results for night trains.

But the goron to shito compartments still exist.