[3] Before the emperor's ascension to the Chrysanthemum Throne, his name (imina)[4] was Tokiyasu Shinnō (時康親王)[5] or Komatsu-tei.

At the time Emperor Yōzei was deposed, Prince Tokiyasu was already Governor of Hitachi and Chief Minister of Ceremonies (Jibu-kyō, 治部卿)[9] According to Kitabatake Chikafusa's 14th-century account, Mototsune resolved the problem of succession by simply going to visit Tokiyasu-shinnō, where the kampaku addressed the prince as a sovereign and assigned imperial guards.

[10] During his reign, Kōkō revived many ancient court rituals and ceremonies, and one example is the imperial hawking excursion to Serikawa, which had been initiated in 796 by Emperor Kanmu.

[15] Kugyō (公卿) is a collective term for the very few most powerful men attached to the court of the Emperor of Japan in pre-Meiji eras.

[17] Emperor Kōkō is well-remembered for his poetry, and one of his waka appeared in the Ogura Hyakunin Isshu: 君がため春の野に出でて若菜つむ     わが衣手に雪はふりつつ kimi ga tame haru no no ni idete wakana tsumuwaga koromode ni yuki wa furitsutsu(Kokin Wakashū 1:21)Unless otherwise noted (as BC), years are in CE / AD  * Imperial Consort and Regent Empress Jingū is not traditionally listed.