Cut the eggplant and onion into bite-sized pieces.
Marinate the eggplant with soy sauce, sugar, mirin, oligosaccharide syrup, and minced garlic for 10 minutes.
Heat vegetable oil in a pan and stir-fry the onion and eggplant over medium-low heat.
Remove the eggplant, pour in the sauce, and let it simmer until thickened.
Place the eggplant and sauce over rice, then top with sliced green onion and sesame seeds.