1. In a large saucepan, combine the sake with 1 cup of water and 2 shiso leaves, and bring to a boil. Reduce the heat, and simmer. Add the shrimp, and poach until light pink and the tails are curled, 3 to 5 minutes.
2. For each serving, spread 2 tablespoons sushi rice in a rectangle. Lay 2 shiso leaves on top, and arrange 5 shrimp, tail end up, on the shiso leaves. Serve with 1 tablespoon soy sauce and 1 teaspoon wasabi paste.