Yanagise Mother

They went traveling around the world in search of a country where they could get legally married since in Japan they can't do that. In fact, Chouji's and Eika's parents are blood-related brother and sister who fell madly in love with each other. At the end, despite being thought that they both died in a politically unstable country, they come back home but still unmarried because that way they can help Chouji and Eika to get married legally instead (since the law doesn't recognize Eika and Chouji as blood-related siblings) which is their ultimate wish.