On the occasion of Osaka no Eki (the Siege of Osaka) which began in 1614, his uncle was required to participate in the battle by his grandfather Morichika CHOSOKABE, so he and his uncle came to Osaka-jo Castle.
1614年（慶長19年）から始まる大坂の役の際、祖父長宗我部盛親から叔父に参戦要請があり、叔父と共に大坂城に赴いた。