The Japanese are gift-givers. If you’re invited to their homes (very rare, as the culture tends to entertain in public places), bring a gift — you hotel’s concierge can assist in this matter if necessary. While we are very fond of the gift melon concept, flowers, candy, or alcohol are also appropriate (besides, a good melon in Tokyo can cost a small fortune). For any kindness done, be sure to be profusely thankful. You may feel awkward, but your return gestures will be remembered and appreciated.