Sailor Pluto has a specail relationship with Chibi-Usa, whom she calls small lady.

Sailor Pluto is propably the one who awaken Sailor Neptune.

In Sailor Moon Super, Sailor Pluto stops time to save Sailor Uranus and Sailor Neptune. She then told the two senshis that what she did would cause her extreme punishment... But then, we don't know what happended to her except that she left the fighting scene (the laboratory of Mugen Gakuen High). I wonder what happened to her?