Shincha, literally "new tea" is the first harvest (first flush) of a Japanese green tea. It is basically the same as Ichibancha, "first tea" and is distinguished by its fresh flavor and sweetness. The term "Ichibancha" will emphasize the difference to Nibancha (second tea) and Sanbancha (third tea). In contrary, Kocha means "old tea" and is a term for tea from last year.
The harvest begins in Kagoshima, a southern and warm area and follows the warm weather like the blooming Sakura cherry trees. In Japan it's said if you drink Shincha on 88th Day after the Spring equinox you will stay healthy all year. New crops are usually late April to May on the market available. Because of its popularity in Japan is Shincha often sold out and hard to get abroad.