Maybe one or two traditional songs from your homeland?
That always seems to go over pretty well (as long as everyone tries their best, and doesn't goof off/ act embarrassed).
A piece of traditional art to present to the guest of honor/ mayor?
Anyway, I suggest something that represents where you're from, and gives a taste of what the country's like.
A letter from your town's mayor (English and Japanese translation) in a nice frame?
Corny? Yes.
Safe? Yes. (unless you pick a bawdy drinking song...
then you're on your own)