Mamoru is confused about his identity. He doesn't know who he is and how he could help the princess that kept appearing in his dream. But when the seven rainbow crystals combined into a silver crystal, the princess of the Moon appears. Mamoru then remembers everything that happended in the past. He then knows that Usagi is the person he needs to protect.

After knowing the truth, Mamoru and Usagi became lovers, but there were many influences that prevented them from being together. Eventhough many situations has happend in his life, Mamoru still faithfully stands by Usagi. In his heart, Mamoru only has Usagi.

Mamoru and Usgai finally got united in the at the very end. In Sailor Stars, Mamoru gave Usagi a ring before he goes to America for schooling. He then upsets Usagi because he didn't reply her letters. This is not Mamoru's fault because he got killed by Galaxia while on his way to America. But, after the final battle with Galaxia, Usagi and Mamoru finally got reunited and thus the ending of Sailor Stars and the anime.