The Two Courts Period (1333-92) was a turning point in Japan's medieval era--a time when an unbridgeable rift appeared in the fragile fabric of Japanese feudal society. On each side stood a separate imperial court, each with its own army and its own agenda. As the schism deepened and the positions hardened, one by one clans and domains were rent asunder until each and every man faced the terrible choice between loyalty and friendship.

Two such men were Nennami Okuyama Jion and Chūjō Hyōgo no Kami Nagahide, who faced each other from across the dazzling divide....