There were times when Kakashi hated Gai.
It wasn't fair to hate him, Kakashi knew. Gai was a good person…in a strange, wacky, out there sort of way. But there was something about him that was just…infuriating.
Possibly, it was the way he forever pestered Kakashi into doing ridiculous challenges, like that sake drinking competition, and when they went to the zoo and Gai then revealed that they were to retrieve a hair from the lion's mane.
Kakashi still had the scars.
Another reason for Kakashi's annoyance could possibly be the obvious lack of fashion sense Gai had. It was embarrassing, honestly, walking around with him, while he was wearing that green suit. He wasn't used to sniggers and people pointing at him, he was used to respect and pretty girls giggling behind their hands.
But these were minour reasons for his dislike. The major reason, the reason that drove Kakashi up the wall, was the fact that Gai was so...happy.
Happy with himself, to wear that suit and not be ashamed. He was happy with his students, despite the obvious way Neji made fun of him and Tenten was embarrassed. He was happy, even though people laughed at him on the street, he was happy when people mocked him.
He was happy, and when he got sad, he always over came it. Kakashi remembered the first time Gai had offered his friendship, he had waved it away without a care, but Gai, being Gai, was ever persistent. He remembered the cake Gai had made for him once. It had been disgusting, and he had told him that. He knew Gai was hurt, but then, without warning, he was enveloped in a hug, with Gai crying, "Oh Kakashi, my eternal rival! How you strive to help me become the best I can be! I am forever in your gratitude!"
Gai was happy, Kakashi knew, even though he had lost his precious people long ago. He had lost both parents, and a sibling. But he was not like Kakashi. He was sad, but then he was happy again. He was strong enough to grow, to be able to love again, to call others his precious people.
Kakashi could never do that. Kakashi could never have precious people. He could have friends, but that was where it ended. He could be happy, but never truly happy, like Gai was.
The fact that Gai was so happy, the fact that he was strong enough to defeat his anguish, to move on, to become strong and always, always have that happy, energetic personality, that was the reason Kakashi didn't like him.
But, Kakashi knew, that was also the reason he liked him. The reason he put up with him.
It was that reason, and that reason alone, that made Gai one of Kakashi's precious people.
But Kakashi would never admit it. No. That'd be just too embarassing.