My hosts at the school - the "San Ban" or "Number Three" class of the Second Grade - assure me that lunchtime is one of the highlights of the school day and shouldn't be missed. "We eat our lunch together in the classroom," seven-year-old Satoshi Yamamoto informed me. "The food is delicious."
The San Ban class is divided into six groups, or "han", each with its own lunchtime responsibilities and duties to fulfil.
One "han" is dispatched to the school kitchen to pick up the steel serving dishes that contain the cooked part of the class's lunch. A second group collects the cartons of milk and bowls of tangerines that have also been set aside for the class.
Back in the classroom, members of another "han" have the task of rearranging the furniture to form clusters of tables while the remaining pupils put on white gloves, overalls and surgical-type masks in preparation for their serving and cleaning duties.
Although school meals in Japan are prepared by a small team of cooks, they are collected and served by the pupils themselves. The meal is a lesson in organisation, hygiene and manners.
A typical hot meal will include rice, some fish or meat, pickles and a few vegetables. Pupils at Tsunoi elementary school also receive a small carton of milk to drink with their meal and a tangerine to eat afterwards.
San Ban's teacher, Toshiko Kobayashi, says she always eats with her pupils in the classroom and that the class has discussions about the sort of food they are eating and where it comes from.
Ms Kobayashi also uses the meal to remind her class of the importance of eating slowly and of appreciating the colours and textures contained in different types of food.
At the end of the meal, the pupils automatically take out their wash bags to wash their hands, and brush their teeth, before going out to the playground.
Japan's school lunch programme was introduced in l954 at a time when many Japanese families didn't have the means to provide adequate nourishment for their children. It is continued today as an integral part of the country's health education programme.
Attempts by some local education boards to cancel their school lunch programmes have been met with furious opposition from pupils, parents and teachers. At Showamachi, north of Tokyo, the education board was heavily criticised when it announced that it could no longer afford to provide a school meals service.
Most families could now provide high-quality lunches for their children, said the Superintendent of Education, Yukio Sekine.
Mr Sekine also suggested that it would be better if mothers spent some time each day preparing lunch boxes for their children. "Fixing a box lunch," he said, "is the most effective way of expressing motherly love."
In the town of Showa, in Saitama Prefecture, parents petitioned the municipal government to retain its school lunch programme after it had been decided that the expense of providing lunch for thousands of children was too great for the municipal budget to bear.
"Times have changed from the days when there was a shortage of food and the school lunch programme was a vital necessity," an official said.
But the Ministry of Education in Tokyo continues to decree that school lunches are an important part of the Japanese school day and have assumed even more importance in today's affluent society.
A growing fondness for western junk food, it is feared, is causing obesity and a decline in eating habits and table manners. The number of overweight children, the Ministry of Health has reported, is higher than ever.
The change in eating habits has already encouraged school boards throughout Japan to employ more than 50,000 dietitians to help ensure that young Japanese receive lunches that are high in nutritional value. The dietitians have also been given greater responsibility for advising on cleanliness following a series of food poisoning cases in the city of Sakai near Osaka when thousands of children became sick after eating eel sushi which had been contaminated by E-bacoli bacteria.
In spite of the problems at Sakai, the school meals programme will be maintained, an official from the Ministry of Health has declared. "Japan," the official said, "has achieved the world's highest life expectancy figures because of its commitment to good food and proper eating habits."