I haven't really seen many people mention this even though it started airing a few months ago. I just watched it a while ago and I really liked it. For those of you that interested, here's the synopsis:
Juuzawa Juu is a delinquent high school boy who just wants to be left alone. One day, he is approached by Ochibana Ame, who claims that she knew him in a previous life, and now wants to serve him as his "knight". At first Juu wants nothing to do with Ame, but after a classmate is murdered, he accepts her help as he looks for the killer.