Hiiro no Isu
Complete | midorikawa yuki | 2000 released
The main character may have made it out alive but it's definitely still tragic. Be that as it may, it's something that I would like to re-read in the future. The plot draws you in, the characters are likeable and none are so easily divided into black or white. Some people have expressed dismay towards the art style but I believe that is just a matter of personal preference as I quite liked it. Don't be fooled by the cover art though. The contents look a bit different (which is all to the better).
Toraware no Minoue
Complete | Hino Matsuri | 1998 released
Yogen no Nayuta
Complete | Fujimoto Tatsuki | 2000 released
Hana to Akuma
Complete | Oto Hisamu | 2008 released
Qualia the Purple