One (ワン ) is Mouse's archnemesis in the series. A top agent and assassin of the Sacred Security Secret Society "Force (4S)" ({{{2}}} ), a secret organization founded to protect cultural artwork valuable towards history. However, the organization has lost its way and has become the largest black market dealers of stolen artwork as well as assassins. He doesn't believe in romantic ideas like immortality.
He fought with the previous Mouse (Sorata's father), and fought to the death with him.
Relationships[]
They are One's subordinates.