GRANCLASS

Hi,
No, there is no JR Pass for Gran Class. Actually, there are comparatively few bullet trains with Gran Class seats. You could upgrade the seats from your pass, but the pass only covers the base fare, and the extra costs would be very high - the seat difference as well as the bullet train surcharge. You'd need to do it at the JR office before you ride each time, which would be a troublesome headache, or keep to a very strict schedule and do it for all the trains with Gran seats you plan to take ahead of time.
For the costs, look on Hyperdia. Under "More Options", be sure to uncheck the Nozomi box since you can't ride that train using the pass. Look under the Seat Fee drop down menu. If you don't see Gran Class, the train does not have it.

Good luck.

Thx for your kind reply,

Another question to ask, if I'm at Shinjuku, do we need to reserve seat at every station passed by or we can reserve from shinjuku directly to Osaka Namba (only 1 time)

SHINJUKU - TOKYO - SHIN OSAKA - OSAKA - IMAMIYA - JR NAMBA

Is Osaka loop line for Tenoji and other loop liner also valid for JR Pass?

Hi,
You only need to do it once - actually, you don't have to do it at all if you just take an unreserved seat. The bullet train does not go to Namba, however - only to Shin-Osaka. Yes, you can also use the pass for the Osaka loop line and Tokyo Yamanote line. But the loop line does not go to Namba. To go to Namba, you can take the Midosuji line subway (not covered by the pass) from Shin-Osaka.

Any guidance for us as new traveler in Japan about how to know if the train or our destination is fully or partially covered by JR Pass or not? Cause sometimes Hyperdia is not very acurate, the search result is different from others information.

Hi,
You can see a list of JR trains that would require a separate charge with the pass here. There are few and not on a lot of main lines.
I haven't seen a lot of cases when Hyperdia gets it wrong. When you run a route through it, if the train appears purple, you know it is not a JR train.
I can't comment further on what you mean without some specific example.

I hope this helps.

Good luck.

"If the train appears purple, you know it is not JR train" does this mean all train icon appears with green colour in Hyperdia must be JR train, right?

Green is fine, aside from the exceptions linked to above.