Introduction: In a world where spirits walk among humans, their presence is a fact of life-and death. Most people can see them. The strongest can fight them. But only one person is completely blind to them.Ryo Kisaragi was born without the ability to see spirits, a flaw that should have made him powerless. Yet, when an unseen force devours his city, he survives what no one else could. The Sentinels-one of many exorcist factions-take him in, but their interest isn't out of kindness. To them, Ryo is an anomaly. A mistake. A threat....