Sailor Pluto is the Soldier of Time and leads a relatively lonely existence guarding the Gates of Time. She appears as a teenager, but in reality she has been guarding the portal for over 1000 years. On Earth she goes under the guise of Setsuna Meioh.

She first appears in the R series as Chibiusa's advisor in the 20th century, and has a special relationship with her, calling her 'Small Lady' (her official title). Chibiusa also shares the feeling, calling Pluto 'Puu' in return.

Sailor Pluto has the power to see through time, either back or forward, although she does not necessarily foretell the future to others. In an emergency she has the power to actually stop time for several seconds, although this power is taboo and it's use incurrs a punishment for Pluto (We don't know what this is, although the English dub says that it kills her to use the power).

As Setsuna on Earth, she enjoys sewing and cooking, and is a long and loyal friend of the other Outer Senshi, Uranus and Neptune. She is also the one who retrieves Hotaru from professor Tomoe in the Sailor Stars series, having forseen the time when her power would be needed.

Sailor Pluto can sometimes seem cold due to her being blunt anf logical (a trait she shares with the other Outer Senshi) but her close relationship with Chibiusa shows her softer side as well. She was also willing to sacrifice herself to save Sailor Venus in the Stars series, showing her loyalties.

Pluto's heart crystal holds one of the 3 talismans that when combined create the purity chalice, a source of great power. Her heart crystal is the garnet orb, which she keeps on the end of her key-shaped staff and is the source of her 'Dead Scream' attack.