Inuyasha is an anime classic that's been watched by millions. The main villain Naraku was one of anime's greatest antagonists. In a surprising twist, Naraku's final wish upon the Sacred Jewel exposed that, in the end, the menacing half-demon wanted what all humans want.
Naraku was created by evil bandit Onigumo, who offered his body unto demons out of his desire to have the priestess Kikyo and the Sacred Jewel all to himself. Though Kikyo knew that Onigumo was a rancid man, she still decided to help him and nurse him when he suffered horrific burns all over his body that left him immobilized. Onigumo fell in love with Kikyo and began to strongly desire her -- but he could do absolutely nothing to make her his with his ghastly injuries. He decided to become Naraku in order to regain the ability to move, along with newfound strength and a near-indestructible demon body. While Naraku had gained a new identity and might, Onigumo's human heart was still beating within him.
Knowing he could not have Kikyo, a jealous Naraku successfully tore her away from her lover, Inuyasha, resulting in Kikyo's death and Inuyasha's imprisonment to the Sacred Tree. If he couldn't have Kikyo, Naraku would make sure that no one could have her. Onigumo's spirit was disheartened when he learned that the demons he had chosen to sell his soul to had enticed Naraku to kill Kikyo. He even said himself that Kikyo was the only person in the world that gave him a reason to live; if she wasn't alive, he had no reason to be amongst the world of the living and would rather be dead alongside her.
Naraku and Onigumo had a very complicated relationship. Onigumo's heart and spirit that resided in Naraku would forever long for Kikyo and the demons inside of Naraku wanted nothing more than to see her dead. In the moment of Kikyo's death, the demon's desire to kill the priestess overpowered the bandit's dormant will to steal her heart. When Onigumo's will began to resurface within the spider demon, it resulted in Naraku being unable to physically harm Kikyo. A powerful human heart was still beating strongly within Naraku. This would even cause the demon to uncharacteristically check on Kikyo from time to time to make sure that the maiden was safe, often disguising his true meaning with threats and promises of her death. There was even an instance where Naraku became consumed with jealousy at the sight of Kikyo and Inuyasha together due to Onigumo's sorrowful heart. Eventually, he cast the heart out of his body.
It turned out the heart had a will of its own. Apparently, it had been fighting to gain freedom from within the body of multiple demons. However, even though Naraku had succeeded in expelling the burden that kept him from moving forward with his plans, he would eventually have to reabsorb his heart. This was so that he could maintain his stability as the multitude of demons within him wrestled to take control. Without the human heart standing in the way, there was nothing to ensure that they would be kept at bay.
After removing his human heart once more, Naraku protected it fiercely. He knew that if the heart were killed, he would perish along with it. As great and powerful as he was, he still had a crippling dependency on the most human part of his very being. While this was explored throughout the course of the series, this fact became even clearer when Naraku made his final wish upon the completed Sacred Jewel. Ironically, the villain's actions up until that point in the series had been fueled by the pain of losing the only true bond he had ever experienced in his life with Kikyo. Kagome revealed this when Naraku hesitated to absorb the entirety of the Sacred Jewel into his being. Naraku's final and failed wish was to have Kikyo's love forever and he even expressed a sense of deep sadness at not being able to join Kikyo in the afterlife.
For all the atrocious acts that Naraku had committed throughout the course of Inuyasha, these evil actions were in direct correlation to obtain a very human desire -- true love. In the end, Naraku was more human than anything, no matter how many demons resided within him.