After his eldest brother Nobuchika CHSOKABE died in the Battle of Hetsugi-gawa River in 1586, he was obliged to contest the inheritance of the position as a family head with a group that proposed his elder brother, Chikakazu KAGAWA or Chikatada TSUNO.
天正14年（1586年）の戸次川の戦いで長兄の長宗我部信親が戦死すると、兄の香川親和や津野親忠を推す一派と家督相続をめぐって争うことになる。