You don't have to read in them in any particular order, there isn't any references in one of them to the other, but they're still the same theme, so...
Cherry Soda and
Bitter Coffee by
hereticpop Aoi & Ruki. I think this might be some of the most original and creative stuff I ever read, and you'll have to find out the rest yourself. I know some of you don't read fanfiction. But really, Cherry Soda? If you have never read anything before, not matter if you want to read or not, this is where you should start. No really pairings there, either.