Akarui is the child of Usugurai Uchiha and Miyuki Senju. Usugurai was not present for the Uchiha massacre. He was undercover in Iwagakure when it happened. There, he had a child, Akarui's older brother. He returned to the village, only to find that his clan was destroyed. He left, however, he took Miyuki Senju with him, as she was a childhood friend and a romantic interest. With her, he conceived Akarui Uchiha, whom he later delivered to Konohagakure anonymously. He was delivered at the doorstep of Kakashi Hatake when he was only 3 months old. Unwilling to raise a child, Kakashi delivered the child to the Nara, who decided to raise him as one of his own. However, he takes responsibility of Akarui and has kept a watchful eye on him for all his life. Akarui was a very abnormal child. He was