Someone should have said something >.< this is a regular novel and not a visual novel.
Read about it here:
http://project.baka-tsuki.net/index....ara_no_Kyoukai
I'm really hoping that Baka-Tsukai group might work on this novel
Here are the covers of the commerical edition of the novel that got released by Kodansha:
Kara no Kyoukai the Garden of sinners part 1
Kara no Kyoukai the Garden of sinners part 2