Tenjō no Hana.

Tatsuji Miyoshi regards Sakutaro Hagiwara as his teacher. Feelings run deeper since he loves Sakutaro’s youngest sister, Keiko, but she rejects him. A decade later and as the Pacific War rages, Tatsuji finds out that Keiko is recently widowed and he divorces his wife and leaves his children and marries Keiko. They honeymoon quietly Echizen Mikuni but their personalities don’t match as Tatsuji is unable to keep up with the more uninhibited Keiko.