as Tuxedo Mask. In the first arc, the group battles the Dark Kingdom, whose members attempt to find the Silver Crystal and free an imprisoned, evil entity called Queen Metaria. Usagi and her team discover that in their previous lives they were members of the ancient Moon Kingdom in a period of time called the Silver Millennium. The Dark Kingdom waged war against them, resulting in the destruction of the Moon Kingdom. Its ruler Queen Serenity sent her daughter Princess Serenity, reincarnated as Usagi, along with her protectors the Sailor Guardians, their feline advisers Luna and Artemis, and the princess's true love Prince Endymion, who in turn was reborn as Mamoru. At the beginning of the second arc, the Sailor Guardians meet Usagi and Mamoru's future daughter Chibiusa, who arrives from a 30th-century version of Tokyo known as "Crystal Tokyo", which is ruled by Neo Queen Serenity, Usagi of the future and has been attacked by the group of villains known as the Black Moon Clan. During their journey, Sailor Moon and her friends meet Sailor Pluto, Guardian of the Time-Space Door. During the climactic battle of the arc, Sailor Pluto dies trying to save the sailor soldiers and Chibiusa was brainwashed by the enemy and turned into the Black Lady, but was eventually reformed and awakens as a Guardian herself—Sailor Chibi Moon. The third arc introduces car-racer Haruka Tenoh and violinist Michiru Kaioh, who appear as Sailor Uranus and Sailor Neptune, whose duty is to guard the Solar System from external threats. Physics student Setsuna Meioh, Sailor Pluto's reincarnation, joins Uranus and Neptune in their mission to kill a mysterious girl named Hotaru Tomoe, whom they identify as the Guardian of Destruction Sailor Saturn. However, when Saturn awakens she joins the final fight against the main antagonists of the arc, the Death Busters, sacrificing her life in the process. With her newly obtained powers as Super Sailor Moon, Usagi restores the Earth and Hotaru is reincarnated as a baby. The fourth arc explores the Sailor Guardians' dreams and nightmares when the villainous group Dead Moon Circus exploits the Guardians' deepest fears, invades Elysion (which hosts the Earth's Golden Kingdom), and captures its High Priest Helios, who turned into a Pegasus and tried to ask Guardians for help. This storyline also addresses Mamoru's relevance as protector of the Earth and owner of the Golden Crystal, the sacred stone of the