"Mokuba and I are related," is Kaiba's response. "If anything, I'm the one whose hair did it first. I'm not fond of it though."

Hence, why Yuugi never knew that his hair curled on the ends. Kaiba didn't want it to. It looked silly when it did, and he had an image to uphold. Even Mokuba, by now, tended towards gelling his hair down.

"I'm surprised it isn't longer."