Read Knife Manga:
Collection of short stories by Kaori Ozaki ("Immortal Rain"), including her debut story. The earliest story in the volume was written when she was sixteen, and the last one when she was nineteen. CAUTION: There is quite a lot of nudity here; it's more art-house variety than hentai, but if you'd rather not deal with nudity period, this probably isn't the book for you. The stories are good, though.