Lifespan: 14xx to ninth month of Eishō 5 (1508) or after Eishō 15 (1518)
Other Names: Motohide
Title: Governor of Shinano, Assistant Vice-Minister of the Sovereign’s Household
Lord: Hosokawa Masamoto
Father: Chōsokabe Katsuchika
Siblings: Kanetsugu, Tsugutaka, Chikaoki, Michitaka
Children: Kunichika, Motoharu, Kuniyasu, Chikayoshi
Chōsokabe Kanetsugu served as a bushō during the late Muromachi and early Sengoku periods. He was a kokujin, or provincial landowner, in Tosa Province in Shikoku.
Kanetsugu was born as the son of Chōsokabe Katsuchika, a kokujin in Tosa. He was the grandfather of Chōsokabe Motochika, a sengoku daimyō and the twenty-first head of the clan. Under the authority of Hosokawa Masamoto, the deputy shōgun, Kanetsugu became an influential figure in Tosa, but, following the assassination of Masamoto in an event known as the Lord Hosokawa Incident, Kanetsugu fell from power.
In 1478, following the demise of Katsuchika, Kanetsugu inherited the headship of the clan and served Hosokawa Masamoto. Nevertheless, Masamoto was the military governor of several provinces and most powerful figure in the bakufu so spent most of his time in Kinai (Kyōto and the surrounding provinces). As a result, Kanetsugu did not frequently meet directly with Masamoto in Tosa. Kanetsugu had the other name of Motohide, with one of the characters received from the name of Masamoto.
Kanetsugu was known as a brave and intelligent bushō, deeply trusted by his band of retainers. Initially, he governed effectively, but, after a prolonged dispute with the Yamada clan of the Kami District, he relied upon the backing of Masamoto and the Ichijō clan, gradually displaying an arrogant attitude. This stirred opposition from the gōzoku, or wealthy families, in Tosa.
In 1507, the assassination of Masamoto in the Lord Hosokawa Incident occurred in the context of broader succession struggle in the ruling Ashikaga family known as the Eishō Disturbance, named after the Eishō era during which it occurred. The unexpected death of Masamoto brought about chaos in the Kinai while, without the support of Masamoto, Kanetsugu was abandoned by his retainers and left isolated. Viewing this turn of events as a favorable opportunity, in 1508, the Motoyama, the Yamada, the Ōhira, and the Kira clans formed an alliance and marched toward the base of the Chōsokabe clan at Okō Castle in Tosa. Upon the outbreak of hostilities, Kanetsugu at first had the upper hand, but, outnumbered by the besieging forces, his supply lines were cut and his allies abandoned him.
Under traditional theory, in 1508, Kanetsugu was attacked by the Motoyama clan and took his own life in his base at Okō Castle, whereupon his son, Senyūmaru (later known as Chōsokabe Kunichika) fled and was raised by a noble and daimyō named Ichijō Fusaie (the second head of the Ichijō clan in Tosa). In 1518, through the offices of Fusaie, Kunichika returned to the townships of Emura and Hataeda and reclaimed Okō Castle. Thereafter, he endeavored for the revival of the Chōsokabe family. Based on recent research, however, at the time of the attack on Okō Castle, Kanetsugu did not take his own life and, instead, took refuge within the province. In 1511, he reconciled with the Motoyama and Yamada clans and returned to his position as the lord of Okō Castle. Around 1518, he transferred headship of the clan to Kunichika.