1. Cut spam into small cubes and fry in a shallow pan until crispy.
2. Add soy sauce, mirin, and sugar to pan. Cook down until it turns into a glaze consistency.
3. To a glass baking dish, add cooked rice, furikake, and spam. Top with kewpie mayo and more furikake. Bake at 450 degrees for 30 mins or until top is nicely toasted.
4. Remove from oven, top with green onion, and enjoy with seaweed.