Cut the kimchi and pork belly into bite-sized pieces.
Put the kimchi, pork belly, onion, and green onion into the rice cooker.
Add soy sauce, sugar, minced garlic, and red pepper flakes, then mix well.
Pour water over the ingredients.
Close the lid of the rice cooker and cook with the 'steam' function for 30 minutes.
Transfer the cooked kimchi stew to a bowl.