Summer☆Salt ~Doutei to Shojo no Fuufu~

The protagonist, Isshiki Kazuto, was heartbroken after his failed relationship with the widow Touko. The one who helped him was Misao, who had once been rejected by him. Misao devotedly supported Kazuto, who aspired to become a teacher, and eventually the two got married. They lived a happy married life, but the story didn't end there.