Can't make the scene if you don't have the green.
The green car is like business class for the bullet train.
Personally any seat on the bullet train is fancy enough for me.
If you like the feel of VIP I recommend the green car seats.
To ride the green for free.
If you can collect points if you have a JR credit card every time you buy a Shinkansen ticket.
You can use the points to up grade your regular seat charge to a Green Seat.