Chibiusa (ちびうさ, Chibiusa or " Chibi -usa", renamed "Rini" in some English adaptations) is a fictional character in the Sailor Moon manga series created by Naoko Takeuchi. She is introduced in Chapter 13, "Conclusion and Commencement, Petite Étrangere", first published in Nakayoshi on February 3, 1993. She is a small child from the 30th century who travels to the past to seek help from the Sailor Soldiers. She later returns, a few years older, in order to train as a Soldier herself— Sailor Chibi Moon (セーラーちびムーン, Sērā Chibi Mūn), translated as " Sailor Mini Moon " in the DIC and Cloverway English adaptations.
Chibiusa's birth name is Usagi Small Lady Serenity (うさぎS (スモール)L (レディ)セレニティ, Usagi Sumōru Redi Sereniti). She is adopted as a member of her mother 's family, using the alias Usagi Tsukino, in the 20th century. She is given her nickname to differentiate from the older Usagi Tsukino, Sailor Moon. The nickname is a combination of chibi (meaning small person or small child ) and her given name, Usagi.