Niou loved the scent of Yagyuu's hair. There were times when he'd get the chance to sniff it, when Yagyuu didn't have his guard up, and being an opportunist, Niou would always take the chance. The scent of Yagyuu's hair reminded him of pancakes for some reason. There were times when his insanity would get to his head and he'd had dreams of biting Yagyuu, just to see if he really wasn't a pancake.
He loved running his fingers through Yagyuu's hair when he had the chance. Yagyuu's hair was soft, and not easily tangled. Usually, it took the gentleman only a stroke or two and his hair was back to normal, looking like it had never left its unruffled state. So, Yagyuu didn't really mind Niou running his fingers through his hair because it could be fixed rather easily.
Niou liked the feeling of Yagyuu's head on his lap. It got heavy at times, but he didn't really complain. Usually, it's him who's the touchy-feely part of their partnership, friendship, whatever-this-was-ship since Yagyuu being the touchy-feely one would just defy expectations of him due to his reputation. Yagyuu had his reputation to keep and Niou respected that.
There were also the times when Yagyuu would firmly tell him to stop it; it being the frequent contact. Then Yagyuu would launch into his rambling about how Niou got really annoying and he'd try to distance himself from Niou. Niou just shrugged it off and waited for Yagyuu to come back and he always did.
Because no matter how much he tried to deny it, Yagyuu needed the insanity that Niou brought into his life. And because oddly enough, it was only when he lay his head on Niou's lap and let him brush his fingers through his hair that he was able to keep sane and momentarily escape expectations.
owari