In the Beginning...
1,000 years ago, in the Silver Millenium, Mamoru was Prince Endymion of earth. He was in love with Princess Serenity of the Moon Kingdom, but a love between the earth and moon could 'never be'. When Queen Metallia attacked the Moon Kingdom, Prince Endymion fought as a soldier, to protect Princess Serenity, and all the other planets in the Silver Millenium. He died, along with Princess Serenity fighting against the Dark Kingdom.
In the Present...
And so Prince Endymion, along with princess Serenity and the other Senshi were reborn on earth. Prince Endymion recieved the name of Chiba Mamoru, while Princess Serenity recieved the name of Tsukino Usagi. As a child, on Mamoru's birthday, he asked his parents if he could go for a ride. During the ride, they tragically fell off a cliff, and only Mamoru survived. In the hospital, the doctors told him he had amnesia, when his memory came back, he still tryed to figure out who he was. Also in the hospital, he had his first earth encounter with Usagi, who gave him a rose. Usagi was there because her mother had given birth to her new baby brother, Shingo. Mamoru lived in an orphanage until the age of 16, when he was old enough to move out onto his own.
Then he started appearing as Tuxedo Kamen, when the Sailor Senshi were in danger. He didn't know he was Tuxedo Kamen, nor did the Senshi. Mamoru finally realized that he was Tuxedo Kamen. Tuxedo Kamen then searched for the 7 crystals, which would supposedly reveal to himself who he really was. He kept having a recurring drea of a princess telling him to save her. After a duel with Zoisite for the 7 crystals, he and Usagi finally found out each other's 'secret' identities. After that, Mamoru was deeply injured by Zoisite, and the Dark Kingdom captured him, and erased all of his earth memories. They brain-washed him into an Evil version of Prince Endymion, now a henchman competing with Kunzite for the Dark Kingdom. Eventually, SailorMoon restored him to normal again, but he had lost all of hismemories of being Tuxedo Kamen, or the Senshi...
With a new villain approaching, the Senshi would now need a new hero. Hence, the Tsukikage no Knight arrived. The Tsukikage no Knight basically did the same thing as Tuxedo Kamen...show up right when the Senshi are in danger, save them, and give a cheesy speech :D. But the Tsukikage no Knight was not exactly Mamoru. The Tsukikage no Knight was a spirit of Mamoru kind of, wich was incarnated when Mamoru lost all of his memories. The Tsukikage no Knight gained all of Mamoru's memories of the Silver Millenium, and of Tuxedo Kamen. at the end of the first part of the R story arc, when Mamoru was um, kind of fainted from the aliens, Ail and Ann's attacks, the Tsukikage no Knight kind of floated back into Mamoru's body and restored all of his memories.
With an even newer villain, Tuxedo Kamen returned once again to save the Senshi. But one day, while Mamoru and Usagi were smoochin', a strange 'lil girl plopped on their heads from the sky, and pointed a *toy gun* at Usagi's head. She asked for the crystal... Later, she was revealed as a girl named Chibi-usa, and she and Mamoru got very attached to each other. Mamoru started having warning dreams of Usagi's safety. They told him to stay away from Usagi, or she would be in danger. He breaks up with Usagi, and he and Chibi-usa start spending more and more time together, which makes Usagi extremely jealous. Eventually, Usagi starts having the same recurring dream and tells Mamoru. They get back together, and they learn of their future as King Endymion, and Neo-Queen Serenity in Crystal Tokyo. It is also revealed that Chibi-usa, or Small Lady, is their daughter from the future. 1000 years to be exact.
There is no real trouble in the S series with Mamoru. He doesn't get brainwashed or anything :D
No other real trouble here either... :D Except for when Fish's Eye kisses him against his wiil, but no biggie :D
Early in the Stars Series, Nehernia breaks a mirror, and thousands
of gold shards of glass fall in people's eyes. One of those people, Mamoru. These shards make
them obsessed with mirrors. You could call them self-centered, or maybe posessed. Mamoru fills
his apartment with mirrors and spends all of his time staring into them. Nehernia then captures
Mamoru, making him totally under her control. Usagi then becomes Eternal SailorMoon and
literally flys off to save him. With Mamoru like that, Chibi-usa starts to fade away. Then
um, Eternal SailorMoon kills Nehernia, and saves Mamoru.
In The Future...
Mamoru will become King Endymion. Usagi will become Neo-Queen Serenity. Chibi-usa is Small Lady, their only child. Together Endymion and Serenity will rule peacefully over Crystal Tokyo.
Ok, so maybe this summary wasn't so brief :D