“Ekiben” is the abreviation for “Eki”/Railway Station and “Ben”/Bento-Lunch box.
These packed lunches are extremely popular in Japan (I counted more than 90 in Shizuoka Prefecture alone!), as not only they make for a very satisfying lunch during a long trip, but they are usually made up with local ingredients, thus offering a good idea of what is eaten in the particular region you are visiting or going through!
I found this limited seasonal (Spring only) ekiben at Mishima JR Station Shinkasen Platform.
It is actually made in nearby Numazu City, one of the major fishing harbours in Japan (it does have a JR Station, but no Shinkasen stops there), and consists of Aji (sebream) sushi.
The lunch includes three types of sushi: nigiri (a piece of fish atop a ball of rice) secured by a band of pickled cherry tree leaf, another nigiri made up of a ball of rice mixed with the same fish inside a pouch made of pickled cherry tree leaf and a sushi maki also envelopped in pickled cherry tree leaf instead of the usual “nori”/seaweed. The fish is caught and pickled in Numazu City, therefore absolutely safe for consumption.
The beauty is that we are provided with a piece of real fresh Wasabi (from Amagi Plateau in Izu Peninsula) with a grater and soy sauce!
You could not find something more typical of Shizuoka Prefecture!