What?! No spam musubi?
http://www.japantoday.com/category/food/view/what-do-japanese-people-put-in-their-rice-balls
Musubi (or onigiri as it's more popularly known) was a staple for me growing up. My favorite fillings were diced takuan or nori paste. I stayed away from the umeboshi ones which were a favorite for many people. I also liked the ones that were sprinkled with furikake. And spam musubi, which was brick-shaped rather than triangular, was of course a huge favorite as well (but that was in Hawaii, not Japan).
http://www.japantoday.com/category/food/view/what-do-japanese-people-put-in-their-rice-balls
Musubi (or onigiri as it's more popularly known) was a staple for me growing up. My favorite fillings were diced takuan or nori paste. I stayed away from the umeboshi ones which were a favorite for many people. I also liked the ones that were sprinkled with furikake. And spam musubi, which was brick-shaped rather than triangular, was of course a huge favorite as well (but that was in Hawaii, not Japan).