I also had Japanese students back then ...
They invited me for dinner most of the time because back then I tutored their kids in the evening.  Their food isn't as spicy as that of the Koreans.  
Both of them value eating food with great health benefits though. 
They didn't just served me soba or somen or udon but a home cooked family dinner style with side dishes, too.  I can't forget the cabbage roll my first Japanese family has served me with Yakitori their mom cooked herself.  
The only difference was - the Japs are more reserved than the my Kr students.  I don't remember laughing out loud on any of the dinners I had with some of my Jap students.  I just remember - there were many moments I forgot my name because their food were freaking delicious - both Korean and Japanese .