Steps
1. In a bowl, combine soy sauce, mirin, sake, sugar, minced garlic, and grated ginger to make the marinade.
2. Add the beef slices to the marinade and let sit for at least 15 minutes.
3. Heat sesame oil in a grill pan or skillet over medium-high heat.
4. Grill the marinated beef slices for 1-2 minutes on each side until cooked through and slightly caramelized.
5. Place steamed rice in a serving bowl.
6. Arrange the grilled beef slices over the rice.
7. Drizzle some leftover marinade (simmered to boil and thicken for safety) or yakiniku sauce over the beef and rice.
8. Garnish with chopped green onions and toasted sesame seeds.
9. Serve immediately, optionally with shredded nori or pickled ginger on the side.