Nami Uraraka Ni, Meoto Biyori summary:

In spring, 20-year-old Natsumi receives a marriage proposal to Takiaki Masashi, who works for the Imperial Navy. Suddenly, she is married to a Navy husband. Their (fairly) inexperienced in house matters, as well as in the affairs of men and women, begin their life as a couple in the highest degree of purity! When the sea breeze blows, I think of you. A story of a couple living in prewar Japan, spring, summer, fall, and winter, humble but gentle.