Rini/Future

Princess Serenity (プリンセス・セレニティ), better known as Princess Rini and Small Lady, is the official title of Rini, the daughter of Neo Queen Serenity and King Darien. Rini is born some after her mother is appointed the Queen of Crystal Tokyo after saving the world from an evil spell that froze the planet.

Early Life
Rini was born June 30 during the 30th Century on Earth, to Neo-Queen Serenity and King Darien. Rini lived a relatively untroubled life in the city of Crystal Tokyo, spoiled by both her mother and father.

She played often with the likes of the Sailor Scouts, Sailor Mars, Sailor Jupiter, Sailor Venus and Sailor Mercury. Of the Sailor Scouts she knew, she was closest with Sailor Pluto, the guardian of time itself.

While her family and friends doted on her, they also wanted Rini to be self reliant and were oftentimes strict with her. But because she was spoiled, she often saw their encouragement as their being mean to her. Despite their instances of tough love, Rini still wanted to grow up and become just her mother, who she considered the most beautiful women in the world.

Attack on Crystal Tokyo
Rini was convinced that her family and friends forgot about her birthday. Intrigued by her mother's Imperium Silver Crystal, she entered the room where it was being kept and removed it from its pedestal. The Silver Crystal appeared to disappear from her hand. Rini panicked, unaware that she had absorbed the Silver Crystal and lowered defenses around Crystal Tokyo. The Negamoon Family, who were banished to Planet Nemesis, took the opportunity to attack the city on the order of Wiseman.

Rini wandered outside during the attack and was almost killed, but her mother jumped into the path of the explosion, protecting her from harm. With the Silver Crystal missing and Neo-Queen Serenity injured, plans were made to get Rini away from danger. Her mother was placed in a state of suspended animation inside a crystal quartz coffin for protection by the Sailor Scouts.

Rini was later taken to see Sailor Pluto, who guarded the Door of Time and Space. Sailor Pluto told Rini to remain in the 20th century until a way to save her mother was found, and the threat to Crystal Tokyo was elimated. Accompanied by her Luna Ball, Rini was sent through the Door of Time and Space to 20th Century Tokyo.

Aftermath
When Rini returned to the future with the past selves of Serenity, Darien and the Sailor Scouts, she was able to save her mother and her home. With the help of Sailor Moon, Rini was able to destroy Wiseman, the orchestrator of the attack on Crystal Tokyo. Rini remained in the future and reunited with her mother, who expressed pride in her daughter's bravery. However, wanting her daughter to be trained as Sailor Scout, Serenity sends Rini back to the 20th century to live with her past self.