Every person born into this world carries a shadow. A creature that grows alongside their human with every experience, both the good and bad. The vast majority of people will never know the truth about these creatures. In rare cases there is the possibility of catching glimpses of these creatures. However, it is often discounted or attributed to other superstitions.

To the gifted or cursed that become aware of these creatures, they are called the Umbra. They come in many forms. Some are guardians that watch over and protect the person they grow with. Others are the opposite, akin to parasites or predators that seek only to satisfy their hunger.

This is the story about those individuals who can not only see these hidden creatures but also work with their own Umbra to hunt down the ones that go rogue.