We have to this restaurant and we have received the worst customer service ever in Japan.
The amount of food is quit much, so we asked for packing and taking back home, they said it's not allowed. Then we asked what if we use our own food boxes, they said even that is not allowed.
It was not about the money, but it's just against our values to throw away a huge amount of food while a lot of people are starving, even here in Japan.
After asking to talk to the person in charge, they told us it's about the food preserving concerns. They don't take responsibility in case that the customer didn't preserve the food in a good way, so it would be old and may cause health problems. Seriously?!
Above that, this restaurant is not foreigner-friendly at all. No English menus.
We were even talking them in Japanese, they just replied: "it's forbidden to pack the food" and turned their backs to us. Very disrespectful way. Unless we showed real anger about that, they won't even bother explaining way. It's just forbidden.
Not recommended at all.