In a large saucepan, combine the water and shiitakes and bring to a boil. Remove from heat and let soak for 20 minutes. With a slotted spoon, remove the shiitakes from the water and set aside. Add broth to the shiitake water and bring to a boil. Immerse the bags of rice into the boiling liquid and boil, uncovered, for 10 minutes.
While the rice is boiling, slice the shiitakes. When rice is done, remove the bags from the pot, cut open and pour rice into a bowl.
Add sliced shiitakes, green onions and soy sauce. Toss to combine.