OK people, help a dumb, old hick out. Today for lunch I went to the local Japanese restaurant and ordered a bento box with hibachi chicken as the main entree. It came with it’s own sauce, but they also brought a little two compartment dish with what they called ‘hibachi sauce’. What was I supposed to do with that? Remember, you are talking to someone that has to eat Japanese food with a fork so be gentle. 
Taste the chicken and rice by itself, taste the sauce by itself, and if you like the food by itself or don’t like the taste of the sauce, you’re good just ignoring it.
If you, like most people, like the taste of the sauce, you can drizzle it over the chicken, or you can put bits of food on your fork and then dip it into the sauce and eat it that way.
Oh, cool. I pretty much just ignored it, but I did dip a couple pieces in it and it was OK. It was just kind of confusing to have another sauce for something that already had sauce on it.