Unlike in some countries, public garbage cans are something of a rarity in Japan. Though there should be a small dustbin at your place of lodging, you should be prepared to carry any trash with you throughout the day, as you are unlikely to find garbage cans on the street. Of course, don't litter! Help to preserve Hamamatsu's scenery for all to enjoy.
Be sure to line up at the back of queues, whether at a restaurant, ticket machine, or for entrance to a location or event.
Speaking loudly on the phone in trains and buses is generally considered poor manners. Also, please refrain from eating food--especially messy or smelly food!--on public transit.
Overnight accomodations are typically priced with the cost per person. Be aware that staying in a room with additional people will likely cause the cost of your stay to increase.