Takes place in my 'X' universe and is chronologically somewhere between 'Sets of Ten' and 'Omne Trium Perfectum'.
As she watched Tsuna laugh at something one of the idiots said, Hayako couldn't help but think back wistfully to when it had just been the two of them. The whispered secrets and hopeless giggles mixed with tears as their legs twined together under that hideous homemade afghan one of Tsuna's neighbors had given her. Their shared kisses and soft sighs of adoration and sadness and regret because they had both known that this thing they had – their girlish, innocent affection for the first person to really notice and care about them that they held only for each other – couldn't last.
Not that Hayako would ever wish to take any of it back. Just like how she would never wish away the group of complete and utter morons that they had befriended. Hayako couldn't remember a time before the boys had entered their lives that Tsuna had smiled so broadly, so easily. It made her a bit bitter, to be honest. Wasn't she enough? She had tried her best to be everything Tsuna had needed in a companion, but she had never been able to get the girl to laugh so brightly.
Tsuna glanced back and caught her eye mid-laugh, and Hayako couldn't help but grin back. There was still the same gleam of affection in Tsuna's eyes as there had been back then, but it was weighed down by the gaudy, heirloom ring on her left hand and by the expectations and obligations pressed down upon them by meddling old men.
The mafia had never been kind to anyone, least of all it's daughters.
A warm presence at her side and the familiar – irritating – laugh of Yamamoto drew her attention away from the girl she would follow forever if she'd allow it, and she felt her grin melt into something not quite a smile but still kind enough. She had enough alcohol in her system that she could probably get away with it if anyone noticed.
"She looks happy," Yamamoto murmured, nodding halfheartedly towards where Tsuna was encircled by a small crowd tittering over her hideous ring. Hayako snorted and hid her sneer behind her flute of champagne.
"She's not; she's just good at pretending."
"Yeah," he muttered a little sadly, "That's what I figured." And Hayako just wants to rip his dumb, stupid frown off his fucking face because he really doesn't understand for all that he tries his best. He'll never understand because he's a boy and his father would never give him away the way her's and Tsuna's had, not even if he had been born a girl because he's not mafia. Not in any way that truly matters outside of the bloodshed.
She immediately tries to reign in her temper, but she knows he noticed. There's not much that he doesn't notice these days, and Hayako is once again plunged in nostalgia and missing the old days where he was nothing more than an idiot boy who was so easily distracted by the sway of her skirts.
Those had been good times. She hadn't had any responsibilities outside of keeping Tsuna company – which had hardly been a chore – Tsuna had been, if not happy, at least content, and Yamamoto had been nothing more than a slight blip on her radar – an easy source of distraction for her once she had decided he wasn't a threat.
And what a nice distraction he had been. Sometimes Hayako wished that things had been different, and that she was allowed to keep those two all to herself. Locked up in her arms and heart – greedy, greedy, greedy. But life didn't work that way. The mafia didn't work that way. Especially not for a princess, a bastard, and an outsider.
A slim hand wrapping around her bicep and soft, brown hair brushing against her exposed arms had shivers wracking up her spine. Hayako turned her head to meet Tsuna's eyes and tried not to let the heartbreaking iwant/i she saw make her burst into tears. She smiled, so sudden and sharp that she knew it looked fake – ihell/i, it was fake – and said her obligatory congratulations to the betrothed of the Vongola Decimo. Tsuna smiled back, a sad twist of her painted lips, and murmured her thanks with a practiced ease.
Hayako vaguely heard Yamamoto offer his own congratulations and felt him move away, the sudden rush of cold air against her side had her eyes watering, but she played it off as well as she could, leaning slightly towards her dearest friend who seemed to exude warmth and gushing in light tones about how beautiful her dress was. She knew that she wasn't fooling Tsuna, but she also knew that she wouldn't mention it. A comforting squeeze against her arm and a slight peck on the cheek was all she was given before Tsuna was swept away.
Hayako watched her go, noting the fake smile and the unusually pale skin, and tried to ignore what felt like her heart eating itself in her chest. She spared a glance around the ball room to see if she could spot Yamamoto, but didn't fret when she couldn't. She'd see him back in Namimori soon enough.