Add 1/2 tablespoon of the oil to the pan. Once the oil is hot, add the onion. Reduce the heat to medium and cook, stirring occasionally, until the onion is lightly golden, about 3 to 5 minutes.
Add the shrimp and cook, stirring, until almost cooked through, about another 3 to 5 minutes. Add the garlic and ginger and cook, stirring, for 1 minute. Transfer the mixture to a bowl and return the skillet to the heat.
Add the remaining 11/2 tablespoons of oil to the skillet, then add the rice, pressing it flat with the back of the spatula. Cook until the rice is slightly crispy, turning it over with the spatula, about 8 to 10 minutes.
While the rice is cooking, in a small bowl combine the radishes, vinegar and salt to taste. In a small bowl combine the soy sauce, sake and sesame oil. Chop the egg and add it along with the peas and sugar snap peas to the bowl with the shrimp.
When the rice is nicely crisped, add the contents of the shrimp bowl and the soy sauce mixture to the skillet and cook, stirring, until the mixture is heated through. Transfer the fried rice to 4 bowls and top each portion with some of the radishes.