Manga title help?

Hello! I'm looking for a manga about a guy who gets kidnapped, he later finds out the person who kidnapped him was kidnapped too as a child and he ends up teaching him to write so that he can get a job, and they end up staying as a couple till they're old where they show a scene of the two in their 50(?)s fishing together, reminiscing. I looked through the entire kidnapping tag but can't find it...