Put the leftover rice into a bowl. If it is too hard, add a bit of water and microwave for about 1 minute
Add in diced tuna, corn, carrots, shredded cheese, furikake, black pepper and mayo into the bowl. Mix together.
Take a small piece of the rice, flatten it and add a bit more shredded cheese. Add another rice on top and shape it into a triangle shape or any shape that you like
Then wrap onigiri with a nori sheets.
Make the teriyaki sauce by combining soy sauce, oyster sauce, ketchup, honey together.
Place the onigiri into the air fryer, space them out. Brush on the teriyaki sauce Heat on 170oC/340oF for 10 minutes. Flip half way and brush on more teriyaki sauce.