Soak rice in a large bowl of water until mostly translucent, about 4 hours. Rinse and drain thoroughly.

Soak shrimp, scallops, and mushrooms in three separate bowls of water until softened, about 15 minutes. Drain all and chop into small pieces.

Heat olive oil in a skillet over medium heat. Pour in eggs, cook into thin layer until set. Flip as needed until fully firm, about 4 minutes.

Roll cooked eggs into a tube shape and slice into ribbons.

In the same skillet, add Chinese sausage and cook until fragrant, about 3 minutes. Combine shrimp, scallops, and mushrooms; stir and cook for additional 5 minutes.

Toast drained rice in the skillet for 2 minutes. Gradually stir in reserved mushroom water and hot water 1/2 cup at a time, letting it absorb after each addition for a total of 25 minutes.

Season rice with soy sauces and sugar. Add egg ribbons and sausage mixture, stir well.