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?

I never heard The special regulation of "eat on The bus"  in Japan. It seems The metor like this. But The long distance bus,  Please just handle ,I would choose not to eat as long as The bus has stops for break. Thanks for all above friends' suggestion.