The story takes place in a regressed modern setting. You play as the protagonist, an 18 year old high school student that is rather skilled at kendo. Your life was always fairly normal, but for some reason you've always felt that the city felt rather dangerous at night. You've heard of a good number of kids at your school have gone missing at night, only to be found dead a few days later. You've even lost a dear friend this way. However, there really isn't much you can do about it until you graduate and join the police force. At least, that is what you thought.
A chance encounter with a mysterious 12 year old girl named Maku Yoshi throws headfirst into the happenings. These people weren't killed by other people. On the contrary, this city has been under attack by an ancient creature known as Veilheart. Veilheart is the legendary fiend of the shadows who was disturbed when a company demolished his sanctuary to make room for a mall. Veilheart himself was killed by the collapsing of the temple, but now he works as a spirit that can raise other ancient artifacts to fight for him, and does so on a regular basis. When this happens, Maku gains the ability to give magical powers through the use of what appears to be a type of trading card.
Finally aware of the situation, you decide to lend your aid to Maku to protect the city from Veilheart, all while continuing a normal life. However even now that you are in the loop, it still feels like there is something far worse lying just below the surface.