After the defeat of Beryl, Mamoru loses his memory of the whole thing, but Usagi and everyone else still have their memories when aliens crash land and begin to collect energy from humans. One alien, Ail, forms a crush on Usagi and the other, Ann, forms one on Mamoru. Usagi goes through this part of the series desparately trying to get Mamoru to remember and keep Ann away from him. As Sailormoon, she heals the aliens, and Mamoru finally gets his memory back in the last Ail/Ann episode. This part of the story was not written by Naoko, but the animators did not want to restart the Sailormoon series and wait for the manga to catch up to the anime, so they invented Ail and Ann.
In the second part of SMR, Usagi and Mamoru finally have a chance at their relationship, or so we think. A pink-haired girl drops down in Tokyo, literally, and lands on Usagi's head. She demands the ginzuishou and points a "gun" at Usagi's head. She shoots Usagi, and it's revealed it's just a toy water pistol. Usagi goes home to find her family brainwashed and suspects the little girl. She asks Ikuko what the "little spore" is doing there and is told, "Don't your recognize your little cousin Chibiusa?" Usagi denies having a cousin, but Chibiusa even brought "pictures" as proof. Chibiusa has a crush on Mamoru, and it doesn't help that Mamoru breaks up with Usagi after his dreams tell him to. Chibiusa claims "Mamo-chan is my boyfriend" now. As Sailormoon, Usagi must protect Chibiusa from the Black Moon family, who are from the future. It is later revealed that Chibiusa is Usagi and Mamoru's daughter.