Tsuna, at a certain point in his life, comes to acknowledge that he was good-for-nothing.
It was a little difficult, a little suffocating at times when he actually tries yet his effort bears no fruit, and he thinks that somewhere in his mind, a part of him has already snapped and had enough of it. Exerting effort gradually turned into something that he feared, terrified of - once more - disappointing himself and the people around him because one way or another, people held expectations that he could never meet. It was just… impossible.
And he continued to believe that for a long while, right up until he gets bullied into jumping down the bridge and realizing that maybe he wasn't entirely good-for-nothing as people has forced and manipulated him to believe.
He remembers being pushed and falling over the metal railing of the bridge and plunging head-first into the ice cold water. Confusion first, shock second, then panic next. He remembers running out of breath, inhaling water and choking, feeling his chest constrict painfully in fear because he kept sinking and sinking no matter how hard he tried to swim upwards and break through the surface. He remembers crying, begging to be saved, screaming into the water up until he realizes that the reason why he couldn't breathe in the first place was because he wasn't giving himself any time to.
And so he takes the time to inhale, and he… breathes. He breathes. Alive and well, despite being a little over several feet under the surface.
It was exhilarating.
His vision clears, mind going quiet at the sight of the water around him, and in that moment, there was no expectations or bullies. It was just Tsuna and the water, and it was the greatest he's felt. He felt safe, felt at home, felt like he belonged and entranced, he stays right there, taking in everything around him with eyes that shouldn't be able to see so clearly through rushing water, before he catches a flash of white and he looks down.
His white tail, a lot longer than he last remembers it, with the fins spanning out a little wider than his arms, flounders gracelessly, seemingly out of control before he reigns it in and gradually starts a slow, methodical movement that keeps him suspended in a certain water level. It was the same color, the same shade of pale white, still an empty canvas, holding no identity or worth yet he couldn't care less. He eyes it with fascination, never really having had the mind to explore this part of himself since there was only so much a child with little to no knowledge of mermaids in the first place aside from fabricated fantasies of beautiful people with tails can do in his small bathtub.
He doesn't feel it, doesn't sense it as he with all the grace of an inexperienced swimmer circled and turned, erratic with every flick of his fin and tail, but fire and flames unfurl from within his eyes, a spark quickly extinguished and buried by a seal long since embedded by a certain man. For a brief second, he thinks he sees the amber glow that colors the tips of his fins a molten gold, but it was gone the moment he sees it and chalks it up to his imagination.
A little over five minutes later, he feels the presence of people approaching the water, prepared to dive and breach the surface that separates water from air, and Tsuna, fearing the consequences being seen in his current state, hastens to will away the transformation. He doesn't know how he does it, doesn't remember much aside from the desperation that gripped his heart, before there was an arm around his middle, taking him to the surface. He gasps, aching to take in air, ability to breathe underwater gone now that his legs were more of skin than scales, breathing ragged and strained.
"Don't worry, Tsu-kun. Everything will be alright. We'll be home soon, okay?" he hears his mother say, her voice somehow penetrating through the blurry haze that was his mind as he feels himself become significantly drier.
He manages a smile, tired but content. Sincere.
"I did it, mom," he rasps out, his eyes barely open from exhaustion. Whether it was due to - having been presumed of - drowning and being submerged underwater for approximately five minutes or his first transformation and realization of what it was like to become what he was, it was all entirely up for debate. "I… shifted. And it felt- it felt great. I felt safe. I felt like I belonged."
His mother inhales, or maybe it was a sob, he couldn't quite tell. It was starting to become difficult to stay awake.
"I'm proud of you, Tsu-kun."
That is the last thing he hears before he finally succumbs to sleep.