Sailor Pluto is of course, a member of the Sailor Scouts. She is also the Guardian of Time.
She is the oldest of all the Scouts and so is of legal age. This is disappointing to Pedo Bear and other pervs who live for any hint of fanservice by the Sailor Scouts. Therefore, there is no necessity for her to appear naked during her transformations, not that there is much to see in her case. And so, her Ayatollah-approved scenes are the only ones allowed to be shown to confused Iranian children.
As a Princess of Pluto, she is tasked with protecting the Time Door. She is absolute crap at this, even letting little kids through. Sailor Pluto also seems to use it for her own purposes, allowing her alter ego to go back in time to take advantage of 25% off sales that she had missed. On the other hand, she has been killed several times but has been able to go back to a time where she was alive each time. Whether the reason is Attention Deficit Disorder or too many all-nighter raves, no one can say for sure.