Can we eat on the bus in Japan?

Long distance bus takes about 3-4 hours. Since it would arrive around 20:00 to the destination, can we buy something eat on the bus? Or it would stop somewhere for rest and eating?

sp;regulation of "eat on the bus"  in Japan. It seems the metor like this. But the Long distance bus, especially for travel, it should be open enough. ,I would choose not to eat as Long as the bus has stops for break. Thanks for all above friends' suggestion.