Onigiri is a Japanese snack of cooked short-grain rice pressed into a compact triangle or ball, usually seasoned with a little salt and often wrapped in a sheet of nori. A savory filling, such as salted salmon, pickled plum (umeboshi), kelp (kombu), or tuna mayonnaise, is commonly tucked into the center before shaping. Compact and portable, onigiri is a staple of Japanese lunchboxes (bento) and is sold widely at convenience stores and train stations as a quick snack for commuting, hiking, or picnics. Regional and modern variations use different shapes, such as cylinders, and fillings like pickled vegetables or salted cod roe, and onigiri has spread internationally as a portable rice snack, sometimes adapted with non-Japanese fillings.