To get the sand out of the clams, add clams to a saline water. Fill a medium bowl with cold water and add salt to dissolve, then add clams. Leave it covered somewhere dark at room temperature for an hour.
Rinse the claims with cold running water. Strain in a sieve.
Add the claims in a large saucepan (or frying pan), add sake. Cover with lid, cook over high heat to bring to a boil. Once it starts boiling, reduce the heat while simmering, and wait for the shells to open. Shake the saucepan a few times. Turn off the heat when all shells are open, pour soy sauce over the clams, shake the saucepan a couple of times.
Serve immediately with drizzle of yuzu juice, even better the optional grated yuzu rind.