It is said that the beginning of his approach to Hisamitsu was placing his letter in Hisamitsu's hands through Jogan Kissho-in, brother of Atsushi, since Jogan, was the Igo partner of Hisamitsu.
篤の兄・吉祥院乗願が久光の囲碁相手であったことから、乗願経由で手紙を渡したのが始まりといわれる。