I love marinated tuna such as pacific bluefin, yellowfin, bigeye, or fatty tuna. They simply melt in my mouth.
I didn't like the dipping sauces shown in cooking books because they were too thick and salty. So I made the sauce a little sweet for my children.
The key is to evaporate the alcohol completely. It is kind of dangerous but I tilt the pot a little to set fire to the alcohol. (Be careful as it flares up).
Enjoy Japanese food around the world.