Emperor Kōan was the 21st emperor of Japan, traditionally believed to have reigned from 770 to 781 AD. He is part of the Yamato dynasty and is known for his relatively short reign during the early Nara period. His era is marked by the continuation of the cultural and political developments initiated by his predecessors. Little is known about Emperor Kōan's life and reign, as historical records from this time are limited. He is often overshadowed by more prominent emperors, but his rule contributed to the stability of the Japanese imperial lineage and the ongoing evolution of the Japanese state.