Their first time is messy and awkward, fumbling attempts in the dark with laughter pressed against heated skin. Tsuna doesn’t know what to do with his hands, is so nervous he can’t seem to get hard at all, and Kyoko keeps giggling so hard she accidentally kicks him in the face. They don’t fare much better the second time, or the third. They always seem a step out of beat, never quite lining up, always missing each other. Tsuna always feels like he’s going to vibrate out of his skin, like there’s something in his gut that’s trying to claw out. He keeps expecting his flames to burst out at any second. After a while he realises he’s so used to fighting his body is wired to it as soon as the adrenaline rush hits. And Kyoko is an adrenaline rush.

In which Sasagawa Kyouko's smile is full of knives, and Tsuna loves her for it.