Easy Rectangular Onigiri

Easy Rectangular Onigiri

I made a smaller and easier-to-eat version of square onigiri rice balls. These are easy to make and a fun way to enjoy different flavors and fillings. They're great to bring to parties!


DIY mold
Milk carton
Plastic wrap
20-25 cm x 15-20 cm pieces, 1 per onigiri
The following ingredient amounts below vary depending on how many onigiri you're making.
Hot cooked rice
about 1 rice cooker cup's worth (150 g before cooking) per 6 onigiri
to taste
Nori seaweed
as needed
Filling for onigiri:
Anything you like
to taste
E.g. Salmon furikake
to taste
If you're going to decorate the onigiri
Nori seaweed, sliced cheese, etc.
as needed


1. Cut the milk carton about 3 cm from the bottom. Open up the carton and cut 3 cm from the bottom of the remainder.
2. Cut the carton into pieces as shown here.
3. Fold the carton like so, with one fold going one way and the other fold going the other way.
4. Fit the piece into the cut off bottom of the carton.
5. Cover each section with plastic wrap.
6. Mix furikake or other ingredients into the rice, and put a mound of rice into each compartment.
7. Wrap the rice with plastic wrap.
8. Press down gently or firmly.
9. Done!
10. Optionally wrap the onigiri with nori seaweed or stick it on, or add sliced cheese and so on.
11. These are Christmas-inspired.
12. Recipe ID: 1275098 is for square onigiri.
13. Recipe ID: 1304858 is for small square onigiri.

Story Behind this Recipe

I wanted to make square onigiri easier to eat, so I halved them.