Looking for a hentai manga (pic unrelated)

I'm looking for a hentai manga. It was about a couple that loved each other, but the guy was sent to fight a war. When he came back, he found out the girl went crazy (I think someone raped her) and she was locked on her house, I think. They started to have sex and she started to recover. In the end, the guy promises her dad to be always be with her.
Pic unrelated.