He is an expert shooter and sticks to the task at hand.He is a part of a large underworld family that is presently undisclosed in the series. His parents taught him how to be a skilled assassin since he was a child. As a result, he is unable to fully understand the parent-child relationship. During his upbringing, his father was both physically and emotionally cruel to him, sending dogs after him to fight and refused to even accept himself as Rei's father. gloomy temperament, gloomy, cold.