Onigiri

Onigiri (お握り) also known as Omusubi (おむすび) is a Japanese (short grain) rice ball snack most commonly formed into triangle or oval shapes and wrapped in seaweed (nori). Traditionally, the onigiri is filled with pickled ume fruit (umeboshi), salted salmon (sake), katsuobushi or any other salty or sour ingredient. If a person pours vinegar on the cooked rice for onigiri, it is transformed into the basis of sushi, a different kind of food. In practice, however, either pickled filling or vinegar is used for preservation of the rice. Since the onigiri is one of the most famed and popular snacks in Japan, most convenience stores in Japan stock onigiri in many popular flavors. Specialized shops, called Onigiri-ya, offer handmade rice balls for take out.

Onigiri is a common snack in One Piece. In addition, Roronoa Zoro's main attack, Oni Giri (Demon Slash), is a pun on this food.