Shincha - 1 oz means new tea. It is the first Japanese green tea harvested in spring and sold while it is still especially fresh, aromatic, and young.
The important thing is timing. Shincha is not a permanent style in the same way that sencha or hojicha is. Once the tea ages past that fresh-crop moment, the name loses some meaning. Think of it as a limited seasonal cup: sweet, green, springlike, and fleeting.