Once upon a time, in a land far, far away, there was a kingdom, named Uchiha-land, which suffered a great tragedy. The heir to the throne, Prince Itachi, killed his parents, the King and Queen, and everyone else who was in any way vaguely related to him. Henceforth, he became king, and known as King Itachi the Crazy and Greatly Feared. He locked his younger brother (the only remaining family-massacre survivor) in an ivory tower so that he may become angry and also because King Itachi the Crazy and Greatly Feared thought he was rather irritating.
And so Prince Sasuke lived in his ivory tower for a good few years; and he trained and became angry, and vowed to kill his brother and end his reign of tyranny. Unfortunately, Prince Sasuke was stuck in his ivory tower, of which the only way in or out was a tiny window at the very top, where Prince Sasuke resided (food and drink etc was all magiced in, as Uchiha-land was a magical kingdom).
Everyday and night, Prince Sasuke wished and wished for the power to leave his ivory tower and kill his brother; until one night, on the eve of his 18th birthday, a fairy of some description apparated into his tower and asked him, "Oh Prince Sasuke, on the eve of entering adulthood, tell me that which you desire the most and I shall grant it to you."
Prince Sasuke's eyes' flared red, and he demanded, "I wish to have the ability to kill my brother. And leave this tower too!"
The fairy-of-some-description frowned, and asked, "What, no knight in shining armour?"
Prince Sasuke glared and shook his head.
"Ah," the fairy-of-some-description looked embarrassed and rubbed the back of her head. "The thing is…well, people usually ask for that…and that's all I can actually do…well, it'll have to do. One knight in shining armour, coming up!"
And with that, the fairy-of-some-description disapparated. Prince Sasuke noticed nothing amiss for a few days, and so presumed the fairy-of-some-description had been a dud. However, at first light on the fifth day, Prince Sasuke happened to be looking to the East- and lo, a valiant knight appeared on the horizon.
Prince Sasuke glared down at the knight, who hopped off his noble steed, and yelled up to Prince Sasuke, "Princess?!"
Annoyed, Prince Sasuke yelled back down, "I'm a PRINCE! PRINCE SASUKE!"
The knight frowned to himself. "Prince Sasuke? Younger brother of King Itachi the Crazy and Greatly Feared?"
Prince Sasuke nodded angrily, and told the knight to bugger off.
"Nope, I've got to rescue you and then ride off into the sunset with you, or something…"
"What part of bugger off don't you understand?!"
And so, a stand-off formed between the two men, which eventually culminated in the knight going Nine-tails and destroying the ivory tower.
Prince Sasuke dusted rubble and dust off himself, and the knight approached him, in human form, and asked, "You okay? Well, at least I rescued you from the tower…"
"You did not rescue me, you oaf, you nearly killed me."
The knight shrugged, and simply said, "Same result either way. Now, time to go into the sunset."
"No!" Prince Sasuke yelled. "I have to kill my brother."
The knight sighed, and conceded, "Fine, we'll go to Uchiha-land, kill your brother, and THEN ride into the sunset together. Happy?"
Prince Sasuke glared furiously at the knight. "There will be no sunset."
"Believe me," the knight said, assuredly, "there will be a sunset."
And so, they travelled to Uchiha-land on the knight's noble steed, and when they arrived they found destruction and misery.
In a very dramatic and angry reunion, Prince Sasuke and King Itachi the Crazy and Greatly Feared fought, and eventually Prince Sasuke prevailed and the tyrannical reign of King Itachi the Crazy and Greatly Feared was over.
Just as Prince Sasuke triumphed, the sun began to set, and so the knight strode up to him, grabbed him and said, "My name's Naruto, by the way." Then he kissed him and they made out as the sun set behind them, because Prince Sasuke had had the hots for the knight all along.
And so, the reign of King Sasuke the Gay began; and Uchiha-land experienced a time of peace and tranquillity; the only concern was the lack of heirs being produced, but King Sasuke the Gay was so happy with Naruto the Valiant Knight that no one brought it up.
And so, they lived happily ever after.