Kekkon x Renai.

Synopsis

Shiho is an unfortunate woman. Her marriage only lasted three days because her husband died. Shiho then decides to be the guardian of her late husband's little brother, Makoto, who was still in elementary school. Nine years passed, and it turned out Makoto is actually the one who's been taking care of Shiho. In his eighteenth birthday, Makoto asks Shiho (twenty-nine years old) to take responsibility and marry him.