Author's Note: One of my reviewers wanted a definition of a Mary Sue, which is a fair point, so here it is from Wikipedia (feel free to skip this if you already know): "A Mary Sue, in literary criticism and particularly in fan fiction, is a fictional character with overly idealized and hackneyed mannerisms, lacking noteworthy flaws, and primarily functioning as wish-fulfillment fantasies for their authors or readers."
Mari Su was the most beautiful kunoichi in the whole world – past, present, or future. She knew this because she was psychic and had used her awesome powers to check out the competition. Her right eye was white and pearly with the Byakugan, and her left eye was a deep passionate red flecked by the telltale markings of the Sharingan. Her third eye, located on the back of her head underneath her magnificent pink-and-blue striped hair, was violet and had the concentric circles of the Rinnegan. Sometimes Mari's eyes switched places, to confuse her enemies and better complement her outfit.
Mari Su's skin was pure white, and it sparkled like the sunlight on the sand on the most perfect beach in all the world. She knew because she'd used her psychic powers to check on that, too. Her figure beneath her delicate silk dress worked with hand-sewn flowers and butterflies was womanly yet girlish – she was so thin that when she turned sideways all you could see of her was her boobs, which were size WW and so perky she did not need a bra. On her highly arched feet were tall leather boots that laced all the way up to the crotch, with stiletto heels so tall Mari Su was basically walking on her toes at all times. This was all right as Mari Su was naturally gifted at ballet.
She carried weapons, of course, as does any kunoichi. There were the kunai which she kept in a Gucci pouch on her belt, carved out of emerald and ruby and sharp enough to cut the wind (very handy in a tornado). She also carried a sword slung across her back. It was tapered elegantly and made of pure gold, which might have made it too soft to serve as a weapon except that Mari Su just happened to be the only kunoichi in the world with gold-type chakra, so that the sword was indeed a lethal weapon in her delicate hands. Usually she didn't have to wield it though, since enemies were usually struck dumb at the mere sight of its beauty – or maybe it was the sun reflecting off the highly polished metal. Whatever, she didn't have to cut with it very often.
Right now Mari Su was making her way to Konoha, to finally deal with her dark past.
As she walked through the front gate the guards both fainted at the sight of her, which was convenient as she'd forgotten her pass. Then Sasuke, having just arrived to wreak vengeance on his homeland, caught sight of her.
"Oh gods!" he cried. "You're the most beautiful kunoichi in the whole world – past, present, or future."
"I know," said Mari Su.
"I was going to take revenge," said Sasuke, "but I think I'd rather marry you. How about it – do you want some of Konoha's hottest commodity?"
Mari Su gazed at him with her lovely mismatched eyes. Tears began to fall from them and trickle down her cheeks, to land in the grass like tiny droplets of crystal.
"I'd like to," she said sorrowfully. "I can tell with my psychic powers that you and I are true soul mates. But I can't because of my tragic past."
"Tragic past?" asked Sasuke, a little put off in spite of himself. No one could possibly have a more tragic past than him.
"Yes," said Mari Su sadly, heaving a sigh that sounded like chamber music, "I was part of the most powerful clan in my village. Then one night the whole village was murdered except for me, because I happened to be away shopping at the time. When I got home I dropped my bags on the floor and discovered that the murderer was—"
"Yes?" asked Sasuke eagerly.
"My pet goldfish Sparkles. It seems he learned all our most secret jutsu by watching, then decided to take out the whole village so he wouldn't have to share me."
Sasuke's eyes filled with tears. It was just like his past, only more tragic. The betrayal of a brother was one thing, but a pet . . .?
"What did you do?" he whispered achingly.
"I flushed him."
"That must have been so hard for you," wept Sasuke. "I mean, I watched my brother die, but at least it wasn't my goldfish. I don't think I could bear that. You are so tragically beautiful, won't you please marry me?"
"No," said Mari Su again, shaking her resplendent head. "I told you, I can't. Because of my past I feel driven to eradicate all ninja goldfish in the world, so that what happened to me can never happen again."
"I'll help you," proclaimed Sasuke. "Since I've given up on revenge after seeing you, I'm not busy anyway. Then we can be together!"
"Oh no you don't!" cried another voice. It was Naruto, who had come to greet his old friend Sasuke just in time to meet Mari Su. He gazed deeply into her eye (he was behind her) and felt himself falling irrevocably in love. There had once been someone else – Sakura, maybe?—but that was all behind him now, as, of course, was the whole Hokage thing. For it was all nonsense compared to this incomparably beautiful ninja nymph.
"If anyone's going to help her," proclaimed Naruto, "it's me!"
"I can tell," said Mari Su with her flute-like musical voice, "with my psychic powers that we are true soul mates."
"Forget them!" called another voice. It was Neji, followed closely by Lee and Tenten. "I'm the one in love with you! Your hair is even prettier than mine!"
"But you are so youthful!" cried Lee. "Obviously you are meant to be with me."
"I can tell," said the lovely Mari Su, "with my psychic powers that we three are true soul mates. But I am not youthful – I'm actually 17.23 thousand years old, I just don't look it because I'm immortal."
"If you cannot be youthful," proclaimed Lee, "then I no longer wish to be youthful. I will cast aside all youthful things!" So saying, he stripped off his trademark green spandex and cast it into the forest. It was a fine gesture, even though he wasn't wearing any underwear. Everyone who saw it was touched, except for Tenten who felt a little sick.
"What is wrong with you guys?" she cried, clutching at her panda-bear buns.
They all turned to look at her.
"You don't find her beautiful?" asked Sasuke, activating his Sharingan so he could kill Tenten if necessary.
Tenten stared at him for a second. "Of course I do," she replied. "But she belongs to me."
"I can tell," said Mari Su, batting her lovely and deadly eyes, "with my psychic powers that we are true soul mates."
"No, she's mine!"
"No, mine!"
"No, mine!"
The argument kept up, and eventually all of Konoha was involved in the fight over Mari Su. Mari Su meanwhile snuck away to find Konoha's goldfish, at which time she encountered Kakashi, Madara Uchiha, and Lady Tsunade trying to hide the devious little fish in a broom closet.
"No!" cried Kakashi. "You may be the most ethereally beautiful female in all of creation, but I won't surrender these innocent creatures to you!"
"Then," said Mari Su, flashing the same blinding smile that had brought down the Tsuchikage, "I can tell with my psychic powers that you three are about to die."
So saying, she drew her flashing golden sword, whose name was also Sparkles, and with a single swing of it beheaded Kakashi, Madara, Tsunade, and each one of Konoha's 13,632 goldfish. Then, mission accomplished, she went back outside.
But the remaining citizens of Konoha had started to fight over Mari Su, and as a result they were all dead. Sakura had punched in Sasuke's face and had in turn been Rasengon-ed by Naruto, who meanwhile had been skewered by Tenten, who then got juuken-ed by Hinata. Like dominoes the rest had all taken each other out, until nobody was left to be Mari Su's soul mate.
"How tragic," whispered Mari Su. "People are always dying over me. Clearly for the good of the world I must nobly end my own life."
So saying, she began to weep and make hand signs simultaneously, and wherever her tears landed they brought someone back to life. She cried enough tears to resurrect the whole town, then skewered herself on Sparkles' razor-sharp blade. As she died her body transformed into rays of multi-colored light and shot off into the heavens. Even in death, she was the most beautiful thing in the world.
After that, whenever any ninja of the Leaf saw a rainbow, they would sigh and say, "If only it was as beautiful as my soul mate Mari Su."