My personal opinion is not to worry about it. If you were invited to somebody’s house in the U.S. and whatever gift you may get for the host will also be appropriate in Japan also.

Just like in the U.S., people you are visiting elderly or young? Do they have family? Kids are young?, etc. All those things which you may consider when visiting somebody in the U.S. will also apply in Japan.

Yes, there are etiquette and protocol when being invited by somebody in Japan which can be different from the U.S. But just like in the U.S., elderly people tend to follow those protocols more than younger people. Formal occasions those protocols are followed and on casual get together those protocols tend not to be followed much.

In formal occasions when protocols are followed, then in Japan people usually think of the host when considering the gift. Also, in formal occasions the person receiving the gift does not open the gift in front of the person who gave the gift. This comes from the idea of what important is the thought of gift giving, not the content of the gift. Especially regarding not opening the gift is still practiced widely in Japan during formal occasions.

During formal occasions a person giving the gift say 粗末な物ですが (Somatsuna mono desuga…, nothing of any value…) which putting yourself down when giving a gift. However, these days such is only practiced only during formal occasions.

However, if this is casual dinner party then what ever gift you will get in the U.S. will also be appropriate in Japan.