Takumi is a high school student. He is withdrawn and is not interested in 3D things. In his town, a mysterious serial murder case happens and people get panicked. One day, when he chats on the internet, a man suddenly contacts him and gives him an URL. He goes to the website and finds a blog image that suggests a next murder case... On the next day, it really happens... Could he really be the one responsible? And where is the D-sword that he is supposed to find?