Tragic yuri:
Your Fault
Although what makes Your Fault interesting in that it shows the point of view of both girls in the story. But ultimately, it ends the way it has to end, because annnngst.
Your Fault didn't feel too tragic to me (because of the way the NTR element was used) but showing the point of view of both girls was interesting. Showing one girl finding out and then showing why the other girl did that made the whole story interesting to read.