An example of Mary-Sue: Aiko Kirei

Please note, that this is just an example of a classic Mary-Sue. I am not saying that if your OC has these traits, they are
Mary-Sues. This is just a small example to keep in mind while creating an OC.

 This is not an actual character. Apologies if I used a name the same as your OCs, please just ignore that.

To help you out if you're a new writer or don't understand the way Mary Sue works, I've written some additional points below which will help you out.

Kirei Aiko (きれい 葵子 meaning "beautiful lovechild").

Background

Kirei Aiko is a child of Uchiha Sasuko and Hyuga Hinato. Her parents moved out of Konoha when her mother was pregnant and moved to The Land of Mist. When Kirei was 5, a shinobi came and attacked them. Her parents were killed, and she was the only one left alive, because she defended herself using the Eternal Sharingan she got when she stole her older brother that was never mentioned before this moment's Sharingan eyes. The murderer turned out to be Deidara.Upon seeing her potential, he has informed the Akatsuki leader, who ordered him to kidnap her. She was taken into Akatsuki and treated like their own. She fled to Konoha where she was taken into the local orphanage where she met Naruto and Sasuke whom she made friends with immidietely. She was hated as a child and everyone was quite scared of her, since she had the ears and eyes of the Kyuubi. There have been several assassination attempts, but they all failed because she kept on killing the ANBU who came for her. She grew older, and graduated the Academy and became a ninja on Team 7. She loved being on the same team as her best friends, but hated Sakura ). All she did was fawn over Sasuke and was really mean to her when Kirei said that people with living parents are jerks. 'Cuz Sakura was totally a jerk after she yelled at her for saying that. With time, Orochimaru heard of her skills. He ordered the Sound Four to track her down and bring her to him. The only thing in the way was the Akatsuki, who were also after her, and the people of Konoha, who promised to defend her at all costs.

To edit since some super-talented writer cannot read a note at the top of the article.

Appearance

Aiko is often described to be quite beautiful, which is also indicated by her name and surname. Her surname was given to her by Kakashi when she refused to join neither Hyuga or Uchiha clan after they were fighting for her. (Which is completely unmentioned in her bio even though this a very important detail to her life) She has two different eyes, one containing Eternal Sharingan, while the other has SUPA Byakugan. They can mend together and create GODU MODU EYES! Stronger then Rinnengan! She is usually seen wearing a black knee-lenght kimono, tied with a red obi and normal, ankle-length ninja shoes. Many girls tend to get jealous over her incredibly petite figure and giant boobs and hips (Even though this is impossible and that she should be anorexic or fat), while she doesn't care what she eats. Ino often stalks her to see if she really doen't excercise or starve herself in order to maintain her looks.

Abilities

To edit since some super-talented writer cannot read a note at the top of the article.

Aiko is able to use Sharingan and Byakugan on extremely high levels. She graduated the academy at the age of 4 and became a Chunin at the age of 5. By the age of 8 she was asked to become Hokage. Most of her skills are unknown to many, due to her being trained in private and individually by Kakashi and Gai. Gai mentioned at some point when she was a genin that she is above his level at Taijustu, and Kakashi's with the Sharingan. She is a genius with Byakugan, even more then Neji.