Name: Chiba Mamoru
N. American Name: Darien
Birthday: August 3
Blood Type: A
Astrological Sign: Aries
Favorite Color: Black
Hobby: Reading
Favorite Food: Chocolate
Least Favorite Food: None
Favorite Subject: Physics
Least Favorite Subject: None
Voice Done By (Japan): Tohru Furuya
Voice Done By (N.A.): Toby Proctor, Rino Romano, Vince Corozza

Guided by the Earth, Mamoru is the love is the love interest of Usagi, though he briefly dated Rei early in Sailor Moon. At first he and Usagi fight like kindergarteners, but when she finds out Mamoru is Tuxedo Kamen, she becomes more serious and stronger in will, mainly because when she finds out, Queen Beryl takes Mamoru to the Dark side. Mamoru has forgotten his past because as a child, he was involved in a car accident with his parents, who died. He also had a reoccurring dream involving Tuxedo Kamen and the Moon Princess. After recovering one of the Nijizuishou, he found out he IS Tuxedo Kamen. He competed against the Senshi and the Dark Kingdom to recover all seven Nijizuishou to find out who he is.

When he was taken by the Dark Kingdom, Queen Beryl erased all of his memories and used him as Prince Endymion and Tuxedo Kamen to fight against the Senshi. Later Sailor Moon won him back to the good side, only to have him taken away again. In the last episode of Sailor Moon (1st season), Sailor Moon won him back, but was killed by Queen Beryl. Sailor Moon avenged his (and the Senshi's) deaths by defeating Queen Metallia.

In the second season, he had lost all memories of the battle with Queen Beryl, the Moon Princess, and Sailor Moon. He was just a normal teenager with a job, and being chased by girls (An and Usagi). Though he didn't fight with the senshi, the spirit of what remains of his memories, Tsukikage no Knight (Moonlight Night) fought in Tuxedo Kamen's place. Later when Ail and An were feeding Usagi and Mamoru to the Doom Tree, Mamoru was hurt very bad and Tsukikage no Knight revealed his identity to Sailor Moon. It was then that Mamoru recovered his memory.

In the second half of the season, Mamoru were a very happy couple, until Chibiusa showd up. She practically took Mamoru away from Usagi by hanging around Mamoru a lot. Mamoru started having painful visions and dreams that forced him to break up with Usagi. The dreams turned out to be King Endymion, Mamoru's identity from 30th century Crystal Tokyo warning him that he and Usagi should not be close. After Sailor Moon defeated the Wiseman and the Dark Moon, Chibiusa was reunited with her parents, Neo Queen Serenity and King Endymion.