Anomalous Matter: Rewind

This is a rapidly developing world that appears peaceful and idyllic on the surface. Yet lurking within it are strange monsters known as the Corrupted. They hide among humans, feed on human blood, and possess tremendous physical strength. Neither firearms nor conventional weapons can harm them.

To deal with the Corrupted, the world established a special agency known as the Bureau of Anomalous Substances, which has specialized methods for fighting them.

The Bureau began taking shape long ago. Its members, known as Sweepers, hunt down the Corrupted in places no one else can see.

They fight by using an artifact called a Contract Lock to summon a Contract Doll and battle the Corrupted. From ancient times to the present, they have protected the peace of their corner of the world.

But these days, the Corrupted are attacking humans less and less often, and the Bureau has gradually let its guard down. Its staff have begun indulging in pleasure, and the Bureau is no longer as dedicated as it once was...

One day, a high school student finds a Contract Lock somewhere. What will happen to him from then on?