Chibi-Usa/ Tsukino Usagi / Sailor ChibiMoon

Although her real name is Tsukino Usagi, she's called Chibi-Usa so it's easier to tell the two odango-atama's apart. In the NA series, she's called Rini. Both make sense, for "Chibi-Usa" means "Little Usagi", and "Rini" is short for "Serena". So it all makes sense. Chibi-Usa is the daughter of Mamoru (Endymion) and Usagi (Serenity) in the future, also known as Crystal Tokyo. She comes back in order to retrieve the Ginzuishou from Sailor Moon, only to end up bringing her back to the future in order to save her mother, which is Usagi's future self. Confused, much? Well, it's the basis of the entire R series. Chibi-Usa is basically an annoying little brat who goes to many lengths to have her own way, can be a pig, and wants Mamo-chan all to herself. Basically, she is a lot like Usagi, so the relation is easily spotted. She also has a little ball, called Luna-P, that follows her around everywhere. Chibi-Usa can make it create many objects at her own whim, while also being able to communicate with Sailor Pluto through it, whom she calls Pu.

In the beginning of Sailor Moon S, Chibi-Usa comes back to train as Sailor ChibiMoon with the rest of the Sailor Senshi. To transform, she uses her mother's old Moon Prism Power routine. ChibiMoon's Pink Sugar Heart attack, although cute and very pretty, is actually quite harmless. It normally serves just to distract the enemy, though, so it can be helpful (sometimes). No one can say that she doesn't try, or is useless, even. She has two combo attacks with Sailor and SuperSailor Moon: Double Rainbow Moon Heartache, and Moon Gorgeous Meditation. There's even an entire season where Usagi and Chibi-Usa have a transformation sequence together. So she's accepted into the team as both a soldier and a friend.