You may bring your own food and beverages onboard for consumption at your seat or private Sleeping Car accommodations. However, you can only consume food and beverages purchased in Dining and Lounge Cars in those cars. Personal food and beverages are allowed in the upper level of Superliner Sightseer Lounges.
Eating and drinking on Japanese trainsYou should eat on trains only when taking a long-distance train, such as the Shinkansen. These types of trains have a tray and cup holder at every seat, and snacks are sold from a vendor trolley. When taking this type of train, it is also acceptable to bring your own food.
So they err on the side of caution, and instruct you not to drink the water, because they can't guarantee that it's potable. Even if the water is great when it goes in, it sits around in an unrefrigerated tank that doesn't get a thorough cleaning every day. That alone is enough to disqualify it for drinking.
If you're seeking privacy and a good night's sleep, the Sunrise has you covered. “Type A” cabins host a single bed, and “Type B” cabins house twin beds. This train also features nobi nobi seats (basic-fare reclining seats), showers, toilet facilities, power outlets, and vending machines.
Talking on your cell phone in the confined spaces of a train or bus is considered rude. If you must use your phone to text message, turn the ringer to silent mode. Also, speak quietly to your travel companions.
Sometimes, it is easier to eat alone than making arrangements with other people, and Japanese society has no problem when people are on their own. It is safe and secure, even if you do solitary dining. For Japanese people, eating alone is convenient. They don't have to talk while enjoying their meal.