Lifespan: Unknown to Eiroku 5 (1562)
Clan: Okabe (descended from the Kudō clan of the Fujiwara-Nanke)
Lord: Imagawa Ujiteru → Imagawa Yoshimoto
Father: Okabe Nakatsuna
Okabe Chikatsuna served as a bushō during the Sengoku period. He was a retainer of the Imagawa clan of Suruga Province. His common name was Sakyō-no-jō and, after entering the priesthood, he adopted the name of Genchū.
Chikatsuna was a close associate of Imagawa Ujiteru. After the demise of Ujiteru, during the Hanakura Conflict in 1536, Chikatsuna allied with Sengaku Shōhō (later known as Imagawa Yoshimoto) and attacked Kita-no-kami Castle and Hanakura Castle (also known as Hanashi Castle). He made significant contributions that led to the toppling of these castles, receiving a written commendation from Yoshimoto.