Sailor Pluto is the sixth Sailor Senshi introduced in the series. Her civilian identity was Setsuna Meiou, or Trista in the English dub.
She referred to herself as the "Soldier of Revolution" (変革の戦士) and the "Soldier of Space-Time" (時空の戦士), under the guardianship of the "Planet of the Underworld," referring to the literal meaning of the Japanese name for Pluto.