Koi Ni Narumade
This is a spin-off of 'Koi no Katachi'.
Bed no Ue no Tengoku
So far I've read the first couple of stories, (up to but not including chapter 3).
Gekkouzaka no Hanayashiki
I'll have to be in the right mood to read this one. It has a depressed and suicidal mc, who is in self destruct mode, and deliberately does everything to push away the one who loves him, (and who he loves). They have a happy end, though, so it might give me hope that even Z can find (and keep!) true love. It seems to be quite well written, so it could be good, plus there's apparently also smut in there, (because one of the mc's methods to hurt himself and others, is promiscuity, just like Z), which might help to relieve the sadness for and annoyance with the mc.
Binan No Dendou
This seems pretty funny, sweet, and a little bit smexy.
Mahoroba Days