In general, said is not considered a meal by itself in Japan. When you go to a wester style restaurant, you will receive a salad in small bowl in Japan. So if you are traveling to Japan and hoping to get a big bowl of salad like you see above, you will not find it.
Of cause you can always go to a buffet restaurant and get as must salad as you wish ... but you are in Japan and you are at buffet, you have much more interesting choices for your meal than a salad.