you don't want to know how long it took me to edit this Sailor Chibimoon - Tsukino Chibiusa

Real Name: Usagi Small Lady Serenity (Chibiusa) 
Birthday: June 30 
Zodiac Sign: Cancer 
Height: ? 
Senshi Position: Inner Senshi, future Moon Princess
Element: none really
Fighting Style: offensive?
Secret Weapons: Luna-P
Guardian: Diana, a grayish-pink kitten who is the future daughter of Luna and Artemis
Favorite Color: red, pink 
Hobbies: collecting rabbit toys 
Favorite Subject: drawing 
Worst Subject: languages 
Favorite Food: pudding 
Favorite Gemstone: diamond 
Family: her parents are Neo-Queen Serenity and King Endymion, Usagi and Mamoru in the future 
Dream: to be a lady 
Seiyuu: Araki Kae

Chibiusa is about six years old, the daughter of Neo-Queen Serenity and King Endymion in the future (Usagi and Mamoru, respectively).  She is sent back to the past to find the Ginzuishou.  She acts annoying, rude, obnoxious, and basically like a spoiled brat when she first arrives.  But, like all characters, she matures throughout the series, and by the fifth series she isn't so bad.  But the brat thing is just a facade, just because Chibiusa doesn't want anyone to see that she's really scared and lonely not being able to see her parents.  Chibiusa does not like to be alone, preferring to be with her "Mamo-chan".  She's in that phase that most little girls go through, the one where they're in love with their own fathers (yes, this happens, or so say the psychologists).  But she realizes that Mamoru is her father, and she backs off a little, realizing that he has Usagi and that she will eventually find someone for herself.  She is very brave, considering what she is up against.  She is also energetic, hyperactive, and curious, and likes to help around the house.  Though she may act immature sometimes, she is really very mature and articulate for her young age.  In the future, she took her mother's (Usagi/Neo Serenity) Ginzuishou because she wanted to be "a real lady", but she lost it and because of that she has a guilty conscience.  She tries to repress her memories, and it works, for the time being.  But Wiseman uses those memories against her, and so as not to spoil all of SMR for whoever hasn't seen it yet, I won't say what happens next. :P 
Chibiusa has a close relationship with her parents (especially Mamoru), both in the past and in Crystal Tokyo. The first time she is sent into the past, she hates Usagi because Usagi is mean to her and treats her like a child. She actually likes the other senshi better than she likes Usagi. But she and Usagi eventually learn to deal with each other. Chibiusa actually wants to be just like Usagi, but this may be partially because Usagi has Mamoru.
Chibiusa is also best friends with Hotaru. She met her when she was sent back by Neo-Queen Serenity the second time, when Serenity wanted her to make friends. At the time Hotaru also had no friends, so she and Chibiusa were perfect for each other. They met in the park one day when the wind blew Chibiusa's hat away. Hotaru, even though she was very weak and got tired easily, chased after Chibiusa's hat and retrieved it for her. Then she healed a cut on Chibiusa's knee. Instead of being disgusted by Hotaru's healing power, as her classmates had been, Chibiusa was fascinated by Hotaru's powers. Soon after that they became friends. 

Moon Prism Power, Make-Up
Chibiusa says this to turn into Sailor Chibimoon

Moon Crisis Power, Make-Up
Chibiusa says this to turn into Sailor Chibimoon in SS on.

Pink Sugar Heart Attack
Chibimoon says this and waves that pink rod she has, and pink heart-shaped fireworks emit from it, usually only annoying her enemy and nothing else.

Luna-P Henge
Chibiusa or Sailor Chibimoon says this and bounces Luna-P around, then throws it into the air and turns it into whatever she wants it to.

Twinkle Yell
Sailor Chibimoon says this to call Helios, the pegasus.

Luna-P Ball
The ball Chibiusa has that looks like Luna.  She uses it to contact Sailor Pluto, or to turn it into other objects.

Prism Brooch
What Chibiusa uses to transform into Chibimoon.

Crisis Compact
A compact that Chibiusa uses to transform into Super Chibimoon

Chibi-Moon Kaleidoscope
Like Sailor Moon's kaleidoscope, she uses this in her attacks.