Kimi no Iru Machi: Tasogare Kousaten is a prequel to the TV series. This was covered in manga chapters 17 and 18.

Eba Yuzuki has mysteriously decided to go to high school in the countryside. But despite Kirishima Haruto's objections, she is living in his home. Now he has to put up with a freeloading city girl and even worse, make sure Kanzaki Nanami, the girl he likes, doesn't get the wrong idea!