Hotaru appears to be a shy, quiet, sweet and innocent girl, but deep inside secretly within her is one of the most powerful Death Buster- Mistress 09... Hotaru eventually grew up and attended the Mugen Gakuen 
(Infinity Academy- this school is an academic selective school, with students ranging from primary to high school all in one building. Her father is actually the Professor and Principal of the school. With the accident with the explosion that occured at the lab three years ago, Sailor Uranus and Neptune disguise as students of Mugen Gakuen and attend at the same school to investigate, which supposely has a strong hold of Death Busters).
In the accident, Professor Tomoe agreed to work for the Death Busters in order to bring Hotaru back to life(for more info, visit Hotaru's past ). The Death Busters' mission was to find the three Talismans (hidden in three individuals' pure heart crystals) to get the Holy Grail. They would then awaken the Chimmoku no Messiah (Messiah of Silence), who would summon their master, Pharaoh 90, to take control of the Earth. And, coincidentally, the spirit of the Silent Messiah was hidden inside Hotaru's body.
Hotaru has no friends because they are afraid of her strange powers of healing wounds she had developed.
This seemed to scare them. Adding to that, Hotaru also had occasional seizures, during which she lost control of her body, and would hurt people without knowing. However, the one who was really behind all this was Mistress 09 being possessed in her body. (Find out more in the Mistress 09Page.)
She is really weak and easy to get tired, resulting her not able to do anything physically strenuous. (That's a reason why her father keeps her in the mansion).
As Pharaoh 90 is using all of her energy, Hotaru is often weak and suffers from fainting once in a while.
Hotaru's life remained dark, until Chibi-Usa befriends her. . .
Chibiusa and Hotaru are always together, so when the daimons appeared, Hotaru was often with them. With her occasional seizures where she lost control of her body, Hotaru unleashed a strange power, killing the enemy.
Sailoruranus witnessed this power during a fight with a daimon, they would often follow her. For the safety of Chibiusa and the inner senshi, Sailoruranus warned them not to go near Hotaru anymore, because her existence is dangerous.
"My dream of our world being destroyed has become more intense," said Michiru.
"We have to find the messiah quickly," responded Setsuna, "If the enemy establishes their messiah of Silence and uses the sacred cup..." The three women considered the consequences.
"Hotaru Tomoe," added Haruka, "She has wondrous power. We have to find out who she is."
"I'm slowly getting a clearer image of the woman with the shining sacred cup," said Michiru. She described her vision to the others, of a woman with a long object in her hands...
"The Silence Glaive!" Setsuna and Haruka were stunned. "Are you sure...?"
"Does this mean that the Messiah of Silence is... the Soldier of Destruction... from the planet of destruction?
"If it's true, we may not have any chance of stopping it," stated Michiru.
"No!" Haruka refused to give in. "If we destroy the Soldier of Destruction before it awakens..." Haruka gritted her teeth. "We have to protect the Earth!"
With Hotaru having strange powers, Uranus, Neptune and Pluto often followed around her. This made the inner senshi think that they were protecting Hotaru because she must have a special type of Pure Heart Crystal they were after.
In Episode 119 "Awakening of the Messiah? The Fate of Starswhen Sailor Uranus, Neptune and Pluto found out that Hotaru was really Sailor Saturn, the Silent senshi of Destruction, they try to kill her, because with her dangerous existence, she can destroy the world, and it would be finished.
Sailor Pluto: I knew it!
Chibiusa: Hotaru?
Sailor Mars: What?
Sailor Venus: It can't be.
Sailor Jupiter: Hotaru-chan
Sailor Mercury: is a...
Sailor Moon: sailor senshi
This caused a problem, because Chibi-Usa wouldn't allow them to and would try with all her might to protect Hotaru. She believed Hotaru was innocent and that she can't hurt them.
"What are you doing?" shouted Sailor Uranus,"She represents Saturn. She's the Soldier of Destruction, Sailor Saturn!"
"If she awakens... it's the end of the world," warned Sailor Pluto.
"Leave her! You don't understand the true horror of the Silence," commanded Sailor Uranus.
"If we don't kill her, Saturn will awaken," said Sailor Pluto.
"Once Saturn awakens," said Sailor Neptune, "the planet will be destroyed."
"Kill Hotaru? That's terrible!" cried Chibiusa, "There must be another way!"
"I knew you would say that," sighed Sailor Neptune.
"There's no other way to save the world," said Pluto, "It's the fate of the stars."
Hotaru suddenly vanished from Chibiusa's arms and reappeared in her bed at home.
"That's correct Pharaoh 90," Professor Tomoe had just finishing talking to someone. The professor looked over at the small dome on his desk.
"That's right," he said aloud, "she's Sailor Saturn from the star of destruction."
"Nobody else could be more suitable as the Messiah of Silence!"
Kaori had taken Hotaru away and no one knows where Hotaru was. When Chibi-Usa went to Hotaru's house to find her, no one was there. The whole house was empty.
"Mugen?" said Raye, "That's Haruka and Michiru's school."
----------------
Setsuna: "Mugen High was established three years ago by Soichi Tomoe. Strange things happen there. So Uranus and Neptune entered as students."
Hotaru isn't our enemy," said Chibiusa. "Hotaru is very gentle. She's a good girl! Please don't kill her!"
----------------
After Chibiusa had a nightmare about Hotaru,
Sailor Saturn's soul returned Chibiusa's pure heart Crystal and thanked her. Pharaoh 90 was defeated at the cost of Hotaru's life. Sailor Saturn sacrificed her life to save the world and to stop anymore furthers damage from occuring. Luckily with the help of Super Sailormoon (the true messiah), Saturn was able to recarnate and have a chance of being a normal person
(Haruka and Michiru took care of baby Hotaru until professor Tomoe had recovered).
After returning baby Hotaru to Professor Tomoe (who had lost his memories about what happened), Haruku and Michiru knew they had something they needed to finish before going away. They went to find Usagi and challenged her as Sailormoon in a battle as they saw her not worthy to become the future Queen, because of her action in giving the Holy Grail to the Silent Messiah, could of resulted to the end of the world.
Eventually Sailormoon had a power that released and Sailor Uranus and Neptune saw her real power.
After that, Haruka and Michiru's mission was completed and they went off...
This is the last time we see Hotaru....for now
Continue to Super Series episode Screenshots
Inside the glass dome, little lights twinkled like stars. The view zoomed in closer. Deep inside the dome, thousands of tiny lights spiraled like a galaxy...
"Hotaru's too," added Mina. "It's supposed to be an elite school where only talented people can get in."
"It's a skyscraper school," said Amy, "With all grades from elementary to university in one building."
Darien looked up from the computer. "Soichi Tomoe isn't just a professor, but also the owner of Mugen."
"As spies," said Luna.
"Exactly," continued Setsuna, "Tomoe is probably related to the Deathbusters"
"Hotaru too?" asked Makoto.
"We don't know," answered Setsuna, "We know Tomoe Hotaru is Sailor Saturn."
"Setsuna," said Usagi, "even though Saturn is the Soldier of Destruction, she's still a Sailor Soldier. There must be another way."
"This is why we don't want you involved in our mission," said Setsuna.
At the end, just before the release of Pharaoh 90,
a sudden overwhelming flood of memories caused Hotaru to break free of the evil entity and become Sailorsaturn. Sailor Saturn's true good spirit and good heart forced all the evil from her, and destroyed Mistress 09 from the inside. She managed to regain control of her body and mind.
