He woke up in an unfamiliar place without any recollection from his past and yet he knew how to identify good weapons and his body can move skillfully when facing troubles. On his verge of breakdown upon seeing himself standing in a pool of blood, a beautiful girl with black hair and eyes appeared. The two agreed and started to travel together with each having their own goal only to find themselves being involved in a huge incident five years ago. Now they need to discover what really happened then and who was behind it.