Also known as Im or Mu, this person is the one who secretly sits on the Empty Throne at the center of the world. Imu, whose gender is unknown, refers to themselves as "Mu" and speaks in third person using formal old school English. The existence of Imu is kept top secret by the World Government of One Piece. Nobody should know about Imu except for the Five Elder Stars (the Gorosei). That's because the Empty Throne symbolizes that there's no one ruling the entire world, but that's a lie.