In San Francisco, many Japanese eateries are thriving, but many are not. The number of new openings are about equal to the closings. Apparently, there are too many Japanese restaurants. But when you go south, the situation is quite different. In cities such as Menlo Park, which is one of the richest areas of the nation in terms of income level, Palo Alto near Stanford University, Mountain View and Sunnyvale, almost all Japanese restaurants are operating successfully. They have increased in number, but the density is much less than in San Francisco. One successful eatery in this area is Masa's Sushi in Mountain View.			It opened in 1989 and was renovated in 1996, when its service style was changed from take-out only to full service. In spite of the change, many customers still continue to buy take-out sushi throughout the business hour. "Sales jumped to almost double," says Masa Uehara, 35, the owner chef, "but profit didn't boost proportionately because of higher labor cost and the invisible loss of food materials caused by greater variety of menu items." Masa's is average size of an ordinary sushi bar with ten seats at the sushi counter and 32 seats in the dining room. The average check amount is $15 including beverage, which is low because menu prices are low.