Early summer is the season for the velvety green ume, perhaps the quintessential Japanese fruit. Known generally as the Japanese plum, the ume is actually a variety of apricot. The plump, deceptively sweet-looking ume is actually quite sour and is seldom eaten raw; instead, it is salt-cured and sun dried for several days to create a purely Japanese creation: the wrinkled pink umeboshi. First, ume are pickled in tubs of salt. Weights are placed on the fruit in the tubs, and after about 20 days the fruit is taken out and spread on mats in the sun. This process is repeated several times, and finally red shiso (perilla) leaves are added to the tubs to add fragrance and a soft red colour. The final result - umeboshi - can be kept for several years; the older they are, the more mellow their taste. The umeboshi has been valued from ancient times for its medicinal properties. The fruit has the reputation of being germicidal, and is thus placed with rice in box lunches to prevent spoiling. Thanks to its generous dose of vitamin C, eating one umeboshi a day is said to ensure good health by stimulating the appetite and helping digestion - it's also considered effective against fatigue. On New Year's Day, an umeboshi is placed in the first morning's tea to assure good health all year long.