In their younger years, Gokudera made sure to critique a certain baseball idiot on everything he did.
Every time, Yamamoto would smile his trademark smile and laugh it off, telling the Italian that he's 'a funny guy,' while Tsuna would give a small scream, telling the bomber that he shouldn't be so mean.
There was one thing, however, that Tsuna would agree with his Storm Guardian on: Yamamoto Takeshi had a crap poker face.
Everyday, Gokudera would comment on his fellow Guardian's inability to lie; to control his emotions; to hide what he was really thinking. He would scold him for constant enjoyment of the 'game' they played; criticize his choice of dedicating almost all his free time to baseball instead of training and the family.
Even as they grew older, leaving school and spending much of their time on missions, Gokudera would continue to pester the swordsman about his inability to lie. So much so, in fact, that when he was told that they, being himself and Yamamoto, were to partake in a poker game in order to gain some information from a group of men hailing from a fairly large family, whom the Vongola considered a threat, without giving away who they were, he had laughed in his Boss's face (though promptly apologized the very instant he managed to stop).
And, as he sat at that poker table later that night, holding his cards in one hand and a cigarette in the other, a small smirk played on his lips as his point was proven.
Yamamoto was being as predictable as ever.
Every good hand he got, a smile would shine in his eyes and on his lips. The bigger and brighter the smile, the better and more promising the hand. Not that anyone decided to point it out, especially not the drunk man sitting across the table from them who was, essentially, a fountain of information, spurting facts about his famiglia every time he or one of his two companions won a hand. Every time he managed to win a hand, the Rain Guardian would lift his glass in a silent toast, the three men opposite him copying and knocking back a mouthful or five.
As the night pressed on, and the shot glasses they had been using were replaced with just the bottles, Gokudera felt a pressing need to use the bathroom. So, at the end of the hand, he returned his cards, stood and left the room, stumbling slightly in his alcohol-induced state as he made his way down the hall. The bathroom was far enough away from the room, and the bomber's sense were blocked enough by the alcohol, that he didn't notice the commotion that was taking place. His mind was not prepared for the sight he saw as he stumbled back into the poker room, the walls splattered with blood; three lifeless corpses sprawled on the blood-stained carpet, clean, precise slices to their bodies easily signaling their cause of death; the calm, smiling man still sitting at the poker table, sipping at a bottle of whiskey with one hand whilst his other was occupied by the blood-covered blade of the Shigure Kintoki.
It was then that Gokudera realized something.
Yamamoto Takeshi would smile at everything he liked.
Yamamoto Takeshi would frown ever-so-slightly when things didn't go his way, before covering it with a smile and claiming 'everything is okay.'
Yamamoto Takeshi was a natural born hitman who would mourn for the enemies he struck down during missions.
Yamamoto Takeshi hadn't changed at all since they had first met.
Yamamoto Takeshi was his own poker face.