Prince Kusakabe, also known as Kusakabe no Miko, served as imperial crown prince in Japan's Asuka period. Born in 662 as the second son of Emperor Tenmu and Empress Jitō, he received formal appointment as crown prince in 681. When Emperor Tenmu fell ill in 686, Prince Kusakabe shared imperial authority with his mother, Empress Jitō. He died in 689 at age 27 before his coronation, receiving the posthumous title Emperor Okanomiyagyou.

He married Princess Abe, simultaneously his paternal cousin and maternal aunt, who later ruled as Empress Genmei. Their children were Prince Karu (Emperor Monmu), Princess Hidaka (Empress Genshō), and Princess Kibi. This lineage proved crucial for imperial succession, with his descendants wielding significant influence into the Nara period.

Empress Jitō assumed the throne after his death and eventually transferred power to his son, Emperor Monmu. His ancestral ties included Emperor Tenji (maternal grandfather) and Emperor Jomei (paternal grandfather), featuring complex intermarriage between imperial lines and descent from the Soga clan through his grandmother, Soga no Ochi-no-iratsume.