[He was most certainly not being gentle, and the intention was for her to move her goddamn fucking cloud hair before he did pull it. Or stick gum in it or something else to fuck with her. He's a petty son of a bitch, but even he knows that he can't just go from zero to sixty on a place with numerous people. His fury comes in a step by step process, like rungs of a ladder, or steps on a staircase. Before she spoke, he was sitting at maybe a two or a three on the Baku Rage Aura scale, but now? Now it's jumped to probably six.

One crimson eye twitches and he purses his lips, fingers gripping his knees to keep from blasting her goddamn, clueless face clean off. Smoke wisps from between his fingers as Katsuki grinds his teeth and tries to remember they're both on a TRAIN. He can't blow his lid until they're all off this tin can. But ON GOD, the temptation is insane.]

...Your fucking head's so full of shitty clouds it's seeping out your skull, you goddamn dumbass. [He snorts, nodding his chin towards her hair.] Keep that crap away from me - tie it up or what the fuck ever...just don't let it touch me again. S'cold.