Ghost hunt - Fuyumi Ono

The students of Ryokuryou High School think they've been playing a fun new game called Orikiki. They have no idea that it's actually a wicked spell conjuring up evil spirits that intend to kill their sensei! Even more troubling is that with each passing minute, the strongest spirit eerily devours the other apparitions and grows ever more destructive. Since the spirit can't be stopped, there's only one way to save the sensei: turn the cure around onto the students who initiate it! Mai and Naru clash mightily on this case, as Shibuya Psychic Research must choose between the sensei and the students... and time's running out!