In 1863, he came back to the political arena of Tosa Domain, won the confidence of Yodo YAMAUCHI, a former lord of Tosa Domain, and learned Rangaku (western studies), seamanship and English studies at Kaiseijo (a school run by Bakufu [Japanese feudal government headed by a shogun] for western studies) in Edo.
文久3年（1863年）に藩政に復帰し、前藩主山内容堂の信頼を得るとともに、江戸の開成所にて蘭学や航海術、英学も学ぶ。