Sailor V is my favorite scout but Sailor Saturn is pretty much tied with her, and she's my favorite scout on Sailor Moon. Hotaru is also my favorite bad guy as Mistress Nine, normal person as Hotaru, and little kid as Chibi-hotaru. She is sweet and quiet and at times quite evil. The only real flaw that I can see is that she like the pink yam-head so much.
When Hotaru was just a little girl she asked her mother "What will I be?" Oh, wait, wrong thing. I'll get it right this time. When Hotaru was just a little girl she died in a tragic lab accident. The evil entity known as Mistress Nine came to her father and said if her would become the servant of her and Pharaoh Ninety Hotaru would live. Her grief stricken father agreed but Mistress Nine deceived him and toke not only him as a servant but his daughter as a host body.
I'm pretty sure Hotaru never knew what had happened that day. She certainly didn't know Mistress Nine was festering within her, though she knew something was wrong. At school she was feared and loathed because of the fact she had a mysterious power to heal anyone who was injured, though it made her really weak. Her school mates found this gross so they avoided and picked on her. One really odd thing about her in the manga is that she was part robot. In one sad part Chibi-usa found out about the robotics that made up so much of Hotaru's body and she ran from the girl. Hotaru thought that because of this she had lost her only friend.
Well, soon enough she became Mistress Nine and ate Chibi-usa's heart crystal. *Tastes like chicken!* Did bad but the real Hotaru won against the bad Mistress Nine and she became the good Sailor Saturn. In a nice show of her telepathic abilities *Hotaru is a light telepath though it rarely shows. Don't believe me? Check the show and they show it a few times.* She used astral projection to go to Chibi-usa and Mamoru to give Chibi-Usa her heart crystal back. After this she enters a portal to Pharaoh Ninety's lair and uses her ultimate attack, Death Reborn Revolution, which destroys everything. Through the strength of her love for Hortaru back on earth Sailor Moon transforms herself into Super Sailor Moon and enters the portal, bringing out the reborn Hotaru who is now a tiny baby.
Michiru and Haruka raise baby Hotaru for a short time until she re- ages until she's old enough to fight. Then she still is raised by them but she doesn't need it so much. It really cute how she calls them Michiru-mama and Haruka-papa. Setsuna also lives with them by this point but I think Hotaru considers her as more of an aunt figure.
Go to the the Dark Realm of Lady Nineteen
You catch a glimpse of a young girl with a glaive and all goes black. When you awaken your home or pehaps in the corridor of characters.