You don't have to use soy sauce, if you don't have it. In that case, just put some salt.
2 cups of clams
1 cup of chopped parsley
1 to 2 tea spoons of soy sauce ( to taste )
1 tea spoon of butter
1/2 cup of sake or white wine
1 cup of water
1 to 2 tea spoons of ground garlic
1) Thoroughly wash clams and get rid of sand before cooking. ( I usually put clams in a bowl with water and cover the lid. Leave it for 10 to 20 min. )
2) Put the clams in a pan. Add wine or sake , water over them. Put the pan over high heat.
3) Cover the lid. When it started boiling and clams are open, add parsley, garlic and butter.
Stir and cook for 2, 3 min.
4) Pour soy sauce over 3). Done !