Gather all the ingredients.
Mix dashi powder, mirin, sesame oil, soy sauce, and white sesame seeds in a bowl.
Add the mixture to the warm rice. Mix everything evenly.
Divide into four equal sections.
Prepare a cling wrap and add the mixture onto it. Then make it triangle or circle whichever you want, but make sure it should be flat.
In a large flat pan, add a piece of parchment paper onto it and turn the heat to medium-low.
When the pan starts to get warm, add the rice balls (the maximum is 4).
Turn the heat to low and cook for 4 minutes on each side or until the surface gets brown color.
After both sides of onigiri are cooked, turn the heat off!
Let's serve! Yaki Onigiri is good by itself.