Confidential Confessions is a shoujo drama series by Reiko Momochi which features several short stories in each volume. The stories deal with true to life subject matter that teen girls face such as rape, suicide and sexual harassment. Often dark, it is a provocative look at the hardships that young woman have to deal with, no matter what culture they live in.
Two girls are thinking about the value of life, and have decided it might be best to end their lives together. In the midst of dealing with their changing bodies and puberty, the two realize they belong together; but what will they decide? If you had to choose the person who you would be with in your last moments, who would you choose?
The first volume of Confidential Confessions has a very similar story to Pure Shadow, but with a bit more depth and (in my opinion) better art. If you like depressing stories about suicide or other 'troubled girls' stories, I recommend both these manga.