Ekiben are boxed meals sold at stations or even on trains. It’s an essential (I would even argue, the best) part of traveling by shinkansen bullet trains. If you’re departing from Tokyo Station, you will find a plethora of ekiben types, which might quickly become a less-than-ideal situation if you’re indecisive or have a train leaving in a couple of minutes.
So, when in doubt, I recommend going for Touge no Kamameshi.
Originally created in Gunma Prefecture over 60 years ago, this boxed meal features tasty and nutritious Koshihikari rice cooked in a secret soy sauce-based broth topped with nine colorful ingredients including umami-rich shiitake mushrooms, tender chicken thighs, flavorful bamboo shoots, a candied Japanese chestnut and more.
The best part? The meal comes in beautiful earthenware that not only has excellent heat retention properties, but makes for the perfect keepsake, as well as a reusable hot pot.
Touge no Kamameshi: https://oginoya.tokyo/en/tougenokamameshi/