Diabolo Volume 1 by Kei Kusonoki and Kaoru Ohashi

There is a rumor that if you sell your soul to the demon Diabolo, you will gain incredible powers... for a time. But on your 18th birthday, you will go irrevocably insane, able to do nothing but do the demon's bidding.

Ren and Rai know the truth of the rumor, for they sold their souls to Diabolo ten years ago, when they were only seven. They wanted to save their cousin, but things didn't exactly work out like they wanted, because their cousin was found murdered, and they got the blame. Even so, they recieved powers that they still bear today. Ren has the power of ultimate defense, and Rai the power of ultimate offense. The only difference is that now they use their powers to save others from their mistake.

However, they find that some people don't want to be saved, while others simply have no hope at all. Their first case is of a girl who thinks she may be pregnant, and is bothered by strange happenings both at school and in the apartment building in which she lives. People in the building are being murdered, and there is a strange, dark dog who seems tied to the tragedies.

The second story is that of a plain girl named Hiromi, who sells her soul through various cruel acts so that a beautiful girl named Arisa will like her and want to be her friend. Rai and Ren try to warn her away from where she is heading, but the outcome reveals that Hiromi and Arisa aren't so different after all. Can Hiromi save herself from becoming beautifully cruel?

The final story in the volume reveals the backstory of Ren and Rai: how they sold their souls to Diabolo, how their cousin was found dead and they were separated, only to find each other almost ten years later, and how they vowed to save other teenagers from their own fate. But can they do it?

I enjoyed this volume, which sets up a terrible fate for the two protagonists. You know it is going to end badly for them, but really wonder if they will actually be able to save themselves, or kill each other before Diabolo takes them over. The stories, too, are full of pathos. The situations they relate aren't that different from what teenagers everywhere go through, and really hit home because of that.

An intriguing first volume, well worth a look.