The main requirement for a good sushi experience is fresh, high-quality fish that is beautifully prepared. But to advance a level -- to jump from good to great -- the meal also has to deliver a little visual drama. At Yama Sushi Bar in Hoes Heights near Hampden, that excitement comes with almost every dish. From colorful rolls to noodles illuminated with tiny blue lights, the food at Yama looks like a lot of fun. And the kitchen can do more than make a plate pretty; the food tastes as good as it looks.