The story is set in a middle school in Shishibone city. Tomohiro Miyajima, the main character of the story, and his group of friends are busy studying for an exam. One day, in search for a thrilling mystery as well as easy money, they take several donation boxes and fabricate a curse to scare everyone: "Ohone-sama’s curse" after scrawling 骨 (bone) all over the chalkboards and spreading rumors of the curse, the donation boxes are quickly filled and the curse becomes a major legend of the school. Of course, only Tomohiro and his friends knew the curse was fake. It wasn’t possible for anything to happen. That is, until they receive a donation of 50,000 yen and a letter to go with it, reading: "Please curse Tanashi Miyoko." Immediately after that letter, bullying and crimes in the school escalated, strange incidents occur, and Tomohiro and his friends are left with a much bigger mystery than they wanted to have, that they are forced to investigate by themselves. What happened shouldn