Kotsuzake is a Japanese cuisine, and is a way of drinking sake.
To make kotsuzake, pick the bones and fins out of a grilled fish after eating it, roast and burn them for a while. Then, put these bones and fins in a cup, pour warmed sake over and taste the it with the unique flavor.
In the Chubu region, a whole grilled fish is soaked in warmed sake and tasted. Usually river fish, such as char and sweetfish, are used for kotsuzake. It tastes like a kind of soup. Because kotsuzake is mild and easy to drink, one should be careful not to drink it too much.
One whole grilled fish can flavor 2 or 3 cups of sake. The fish used for making kotsuzake can be eaten like an ordinary grilled fish by adding salt, soy sauce or other seasonings. Such fish has a rich flavor of sake, which goes very well with alcoholic drinks.