In a medium sized pot, bring about half pot of water to boil. Add abura-age and boil for 1 to 2 minutes. This is to remove excess oil. Remove abura-age and let cool. Squeeze out excess water, and cut each abura-age into half. Gently pull open the slit to make pouches.
Pour away water used to boil abura-age. Bring 4 cups of water to boil. Add dashi, soy sauce, sugar, and sake. Return tofu pouches back to pot. Simmer for 15 minutes. Remove and drain tofu pouches.
Mix vinegared rice with sesame seeds in a wet bowl or tub. Wet hands, take a little rice and shape into a rectangular block. Click here for vinegared rice recipe.
Open one tofu pouch and insert the block of rice. Press the edges together to close the pouch.
