From my artwork THE JUSTICE LEAGUE OF ANIME. I painted each of the seven characters there separately, and here you can get a better look at each of them.
Comment and +fav if you want, but make sure you check out and do the same for the original artwork. [link]
Here is the story of how this character joins the Justice League. Read them in order.
Usagi Tsukino thought she had lived a fairly normal, boring life. She somehow managed to coast her way into college without ever really applying herself. Aside from all the typical high school drama regarding her boyfriend Mamoru, there was really nothing notable that she could remember from her teenage years. But the more she thought about it, the more this bothered her, because something seemed like it was missing. She asked some of other people she knew if they ever felt this way, but no one seemed to care. This bothered her too, and she had been noticing that just about everyone had become increasingly more complaisant. Just what had gotten into everybody? Was this it?
While walking home on a cloudy day, she happens upon a stray cat. She picks it up and starts playfully talking to it, only to find that the cat can talk back! As the cat speaks, Usagi is enveloped in a bright, starry background, while images of the past appear before her. It is no coincidence that Usagi found the cat, because the cat tells her that, years ago, she was a magical heroine called Sailor Moon, and that she and her friends saved the world from evil. When the battle was over, all of her memories were erased. Usagi was understandably skeptical, yet somehow, she felt a sense of familiarity. When a flash of magic transformed her into Sailor Moon again, she knew that it was all true.
The cat told her that Sailor Moon was needed once more, to bring love and justice to world after the spirit of humanity has been corrupted. Last time, she was joined by others, but now there was only enough power in the cosmos to restore Sailor Moon alone.
"You mean I've got to do all of this by myself?"
The cat replied "No, don't worry. I've made sure that you won't be on your own."
The cat hopped out of Usagi's hands, and the scene faded back into reality. Usagi looked up and saw the clouds parting, revealing the gigantic space ship Arcadia.