THE MOON BRIDGE

After Pearl Harbor, Ruthie's life at school changes: ``war'' has become very real. Her favorite teacher loses her fiancÇ in the Philippines; a new friend of Japanese descent, Mitzi, is threatened by schoolmates and then interned with her family. Ruthie finds it difficult to grasp the changing alliances: former best friend Shirl proves to be a bigoted bully toward Mitzi, while her beloved ``Japanese Tea Garden'' becomes ``Chinese'' for the duration. Several years later, when Ruthie and Mitzi meet again, there are hints that their friendship has survived. Savin's story is saturated with period references, enlivening San Francisco's vistas with wartime details. But the two girls are little more than types (the good, understanding American; the bewildered victim of malicious government policy), while their friendship seems contrived to depict casualties of the home front; the sentimentality never blossoms into genuine emotion. (Fiction. 9-12)