Wash the bean sprouts thoroughly and remove excess water.
Cut the pork belly into bite-sized pieces.
Grill the pork belly in a pan until golden brown.
Add soy sauce, mirin (cooking wine), and sugar to the pork and stir-fry.
Add bean sprouts and stir-fry quickly over high heat.
Place the stir-fried bean sprouts and pork on top of rice.
Finish with an egg yolk or soft-boiled egg on top.