Disclaimer : I don't KHR! and any of its characters, unfortunately.
To Miura Haru, Hibari was like a mystery. Sure he was scary and dangerous, but she couldn't find it in herself to believe that he was truly heartless. She regarded him as a human being, even if her friends think otherwise. After all, he barely 'kamikorosu' people and she noticed that he was compassionate to small animals. He treated Nami Chuu like his own home, protecting it from harm and such. After all, would you want your home to be destroyed? Probably not. Plus, there were other small details that Haru noticed that made her think that Hibari wasn't as scary as he looks.
His favorite food is hamburger steak. He hates sweets but tolerates chocolate. He prefers to be alone, period. He HATES crowds. He gets bored easily. After all, not much happens around Namimori. He loves a good fight every now and then. His favorite color's purple. He doesn't talk much, except for the occasional 'kamikorosu' and very few times, 'wao'.
You might think that Haru knew everything about Hibari, but she thinks otherwise. What about his parents? Hobbies? See, Hibari was a mystery, waiting to be revealed. And Haru made it her mission to unravel this dangerously interesting mystery.
To Hibari Kyoya, all herbivores are annoying. Except for that Miura Haru girl. She was an exception. There were many times he thought of her as a herbivore; loud, a bit too cheerful, and sometimes, annoying. But, there were times he felt the true carnivore in her. Like when she would argue with Gokudera, he'd feel her inner strength. In Hibari's onyx eyes, he felt that Haru was a carnivore hiding in a herbivore's body. Like an illusion.
She would fake tears with the loud volume in her voice so no one would notice her doe eyes tearing up. She'd laugh just to cover up her sobs. She would smile through her frowns. She could convince anyone that she was all right even if she's broken inside. The truth of her real self is all covered up by deception. Hibari knew that deep down, Haru must have known by now that the herbivore Sawada Tsunayoshi loved Sasagawa Kyoko than her. After all, an illusion covers up the truth. And Miura Haru was an illusion.
Hibari made it his goal to reveal the truth behind her illusion. Why was she hiding her feelings? She had the potential to become a carnivore, but was stuck in the herbivore position. After all, it was a bit lonely to be the only carnivore in a pack of herbivores. In his mind, it wouldn't be that bad to have a fellow carnivore. Miura Haru was an illusion and Hibari Kyoya intended to discover who she really was.