Uchiha Izuna kissed the red-haired beauty who had shared his bed once more before he got up and dressed. He knew that his brother would be having words with him about this later since the Uzumaki were allies to the Senju, and therefore it was quite possible that the woman he'd met during one of his less stressful missions was a spy. He would have stayed with her longer, but he had to get the younger cousins he was training back to the main camp.
Several miles away in the main camp, Uchiha Hikaku was giving a particularly attractive blonde haired, blue-eyed camp follower a kiss and a trinket in payment for the wild night they'd spent together.
Nine months later in two different countries, two different women gave birth. One woman gave birth to a lovely daughter with red hair so dark it was almost black and intense dark eyes, the other gave birth to a handsome brown haired black-eyed son who was the spitting image of his father except for the fact that his hair was a much lighter shade of brown. Neither child met the other in their lifetime, and neither child developed the Sharingan. Unlike the Byakugan, the genes that activated the Uchiha Kekkei Genkai were usually recessive in Uchiha/non-Uchiha pairings.
The children's children didn't meet either. The dark haired beauty made a name for herself on the battlefield, and eventually settled down and married another Uzumaki. The brown haired boy grew to be a rather average shinobi, and married a platinum blonde knockout while he was still in his late teens. The dark haired beauty had a rather lovely daughter with the usual Uzumaki hair and features along with several healthy sons. The brown haired boy had a son who like his father before him bore the family name of Namikaze, and who had been born with his mother's blond hair and his grandmother's sky blue eyes. Neither child showed any sign of the Sharingan, though one of the Uzumaki girl's brothers did shortly before he died on the battlefield.
It was the children's children's children who met. Izuna's daughter's daughter's daughter who had been born with a rather lovely set of the standard Uzumaki features had also been born special, and for that reason had been selected to be Senju Mito's successor as Kyuubi Jinchuriki. Hikaku's son's son's son who had been born with his mother's sun yellow hair and his father's sky blue eyes had not exactly been born special, but he had grown up to be so. Both ended up growing up together, falling in love, and marrying. Neither showed any signs of having the Sharingan, though there were some questions over exactly how Minato had been able to keep up with what was going on while using the Hiraishin to kill fifty to a hundred enemies practically at once.
Minato and Kushina had a son together. When the boy was twelve, he had gone to a land called Wave. While there, he ended up in a seemingly life or death battle with a much faster opponent. In the dome of ice mirrors, two pairs of eyes began to be able to track a masked ninja more easily. Eventually, two pairs of red eyes with black tomoe spinning in each of them found each-other. When that happened, all Uchiha Sasuke could do was stare and go WHAT THE FUCK? !