Aiteru Door kara Shitsurei Shimasuyo

Synopsis

This time focusing on the two elder brothers of Kenzou Honda... Shouichi Honda goes to the Asian imported product shop to collect the tax. There he happens to meet an importer, his younger brother, Junji who had run away from home. When Shouichi returns home, Junji is already there having a card game with their parents. They realize how their feelings have not changed since they made love only once 10 years ago. Included is an extra chapter with the three Honda's brother and a side story, Diary of an Errand. (Source: MangaUpdates)