Prodigal Son by kestrelsan, Tatsumi/Murakoshi, R. They have a lot to work out.
She really captures their awkward, uneven (also hot) relationship. Go, read, love. ♥
If you haven't checked out Giant Killing, I would really recommend it. It's a sports manga and anime about J-League soccer. So actual grown up men instead of boys (well, except Tsubaki!). In order to turn the club around, they hire a new coach who previously played for the team. And Things Ensue. You can watch Giant Killing on Crunchyroll. Murakoshi (see icon), the team captain, is voiced by Okiayu Ryoutarou and Tatsumi, the new coach, is voiced by Seki Tomokazu in case that lures you. :)
I will post my own exchange story in a couple of days. I still have to think up a title!