When Trunks was eight, he became one person.
He thought he was one person already, but then he became someone else entirely, and it was someone better. He didn't have to be lonely because his dad was harsh or his mom was distracted. He didn't have to worry about being strong enough, because now he was the strongest of all.
He didn't have to worry about anything, because Goten was there with him.
When Goten was seven, his entire family died.
He thought he didn't know how to live without his brother, and then his mother died.
He never knew his father. His father was a spectre of greatness that returned, larger than life and golden good, for a single snapshot of time. Not for Goten, but to fight.
Goten thought he would drown in a sea of grief and anger he didn't know how to swim through. He couldn't understand the dismissal of the adults around him, the easy reliance on these stupid, magical artifacts to put his family back together.
He cared that they were gone now.
Trunks reached out his hand, shadows of his lost father in his eyes, and Goten took it.
When Goten was eight, Trunks found a girlfriend. He didn't like her.
He couldn't figure out the swirling mess of tension in his stomach. He felt like there was a word for it, something simple and obvious, but all he knew is that it made him feel unhappy. He smiled and laughed and played with his friend as he always had, and he told himself that it was important to be kind even when he didn't like someone.
When Trunks was ten, he and Goten pressed their faces to a window. Inside, his mother was sweaty and messy and not at all what she normally looked like; his father actually smiled at the bundle she carefully passed over to him.
"I want a little sister!" Goten complained next to him, frowning at the twice-over parents.
"Pan is almost like a little sister!" Trunks shot back, defensive and territorial. "And she'll be more fun sooner. Papa said that babies are super boring."
"Pan isn't boring," Goten said, shoving a shoulder against his friend. He rethought and added, "Sometimes she's boring."
"This is better, anyways," Trunks continued confidently. "Now they can be friends, and we won't have to worry about them."
Trunks was bad at sharing.
When Goten was ten, he was terrible at math.
The numbers always seemed to twist and muddle in his brain, dancing on the page before his eyes. He was fiercely jealous of Gohan's ease with his studies and success in academia. Trunks seemed to find everything easy, too, but for some reason Goten didn't mind so much about that.
It meant that his friend would come over to help him study, heads bent together, and Goten could feel that warm flutter in his stomach like butterflies that he didn't quite understand. He liked it, though. He liked the way Trunks would sit close, their hips just touching on his bed as the older boy pointed out something on his textbook and tried to explain it.
Trunks wasn't actually good at explaining things; he was too impatient, too bad at understanding the way the numbers wouldn't work in Goten's head. He'd sooner do Goten's homework for him than successfully lead him through some new concept.
Goten didn't mind.
When Trunks was twelve, he thought he was going to die.
Not like when his father drove him to the brink of exhaustion during training. Not even like when he'd actually died, so many years before.
Trunks wanted to die because all he could think about was his best friend. And how the sun looked on his features when they were out hunting down adventures in the forest. Or the way Goten snorted into a laugh when Trunks said something particularly funny. Or the way that his friend would step forward at school, stubborn-jawed, when some bully was harassing a weaker kid. Especially the way that Goten would never touch the other kid; he just wouldn't let him touch the sap behind him, either.
When Goten was thirteen, he was miserable.
Trunks, a year ahead of him at school, was endlessly popular. Girls fawned over his soft hair and clear eyes and sharp, handsome features that looked more like his father's every year. He excelled at every one of his classes while Goten, well-liked for his friendly nature but not exactly drowning in attention, struggled just to pass.
Then one day in Trunks's room, his friend looked over at him and said, "Emi wants to kiss."
Goten stared at him, feeling a rush of jealous heat color his cheeks. "What?"
"Emi wants to kiss," Trunks said again, "and I don't know how. It's weird! What are you supposed to do with your mouth?" He stared at Goten and said, "You should help me figure it out."
Goten had never been able to say no to Trunks.
He felt his stomach flip when their lips brushed. The kiss was messy and awkward and wet and perfect.
When Trunks was fourteen, he was terrified.
He couldn't keep kissing Goten, so he kissed girls instead, because that was easy and light and if they cried sometimes because he couldn't figure out how to care enough about it, he didn't really know what to do about that.
One particularly annoyed girl huffed and puffed at him, saying, "Kami, why don't you just date Goten? You two are attached at the hip anyways."
Goten laughed beside him, and Trunks flung his arm around his friend, giving her a thumbs up. "What, like we haven't been dating this whole time?"
Goten laughed again, but Trunks could feel his friend's shoulders tense beneath his arm. He slid his arm away, his heart aching.
When Goten was fifteen, his best friend stomped and raged about another fight with father, about impossible demands and unreachable standards. Goten watched and wished that his own father cared so much.
He saw the shimmer of angry tears fracturing blue eyes and reached for his friend's hand. Trunks's eyes flashed with an impossible, undirected anger that he didn't have room to keep inside. Goten stepped closer, fingers laced together, and curled an arm around his shoulder until he was spent.
When Trunks was sixteen, he set a hand on Goten's shivering shoulder as the younger boy hugged his knees to his chest and refused to cry.
"He's always leaving," Goten said quietly.
"I won't leave," Trunks told him. He tugged his friend to his feet, smile flashing. "Come on," he said, and they danced into one person where neither of them was alone.
When Goten was seventeen, Trunks slid a hand down his stomach and told him it didn't have to mean anything if he didn't want it to.
Goten didn't know how to tell him that it meant everything.
When Trunks was eighteen, Goten took his face between his hands and told him everything he was afraid of. Trunks crushed him to his chest, his fingers curling in his dark hair, and kissed him and kissed him and kissed him until he couldn't breathe.