Cut the pressed tofu into 7 even slabs resembling a rectangle shape.
In a large baking dish add the soy sauce, oyster sauce, rice vinegar, sugar, garlic powder, and whisk. Next, place the tofu down on the dish evenly and marinate in the refrigerator for 20 minutes, take out, flip, and marinate for an additional 20 minutes. For even more flavor, marinate for 1 hour on each side.
Heat a large non-stick pan on medium heat. Once hot, add a little oil and tofu. Drizzle a little of the leftover sauce on the tofu. Fry on both sides until golden brown.
Assemble the tofu musubi using a musubi maker press. If you dont have a press see notes. Lay out one piece of nori horizontally with the shiny side down. Place the musubi mold down in the middle of nori vertically. Add the rice evenly in the mold, about 1 1/2 inches thick. Press the rice down using the flat part of the mold making an even pressed layer of rice.
Place the fried tofu on top of the rice and remove the musubi mold. Wrap the nori around the rice and tofu. Repeat until you have assembled all of your musubi's.