When they met with each other third time, the friend showed Ryoma a handgun which he had bought, but this time Ryoma took a foreign book on international public law out of his internal pocket and said to him "From now on, we must know the world."
三度再会したとき、旧友が購入した拳銃を見せたところ龍馬は万国公法（国際法）の洋書を取り出し「これからは世界を知らなければならない」といわれた。