Emperor Kōan Japanese emperors 2019.09.04 2019.06.26 The sixth Emperor of Japan. Emperor Kōan inherits the Y gene The period of reign 392 – 291 BC Another name 孝安天皇(Emperor Kōan) 日本足彦国押人天皇(Yamatotarashihikonioshihitonosumeramikoto)大倭帯日子国押人命(Ooyamatotarashihikokunioshihitonomikoto) Mausoleum of Emperor Kōan