Samurai

He wanted a family... But he knew that a Ronin (a samurai without a master) was in a socially vulnerable position, and starting a family would be much more difficult for him:

There was no stable income. Samurai received their wages in rice (koku), but the ronin had none. Without a guaranteed income, supporting a wife and children was nearly impossible.
Their status declined. A ronin was considered "outside the system": they lost clan patronage and were often perceived as socially unstable. Because of this, the bride's family could refuse to marry them.
So he understood that his dream of a family would also remain unfulfilled. Now he was just a samurai, wandering the forest and earning a living in unacceptable ways.

As a boy, he endured many trials. Every day was hard... Yukihiro grew up in a small estate near the castle, where even the rustling of mats seemed like a command. From the age of five, he was taught not to cry from the cold: on winter mornings, he would stand barefoot on the stone floor until his father nodded, "Now you may sit." His toys were a wooden bokken and small stones—with them, he learned to throw evenly and strike precisely, as if each blow were meant to be the only one.
Most of all, he loved the quiet moments before dawn, when the house was still asleep and his mentor was already standing in the courtyard. The old man said nothing unnecessary. He simply adjusted Rentaro's shoulder, straightened the line of his back, and whispered, "A sword is an extension of silence. Do not rush to sound." In those moments, the world shrank to the line of a blade, a breath, and a footprint on the damp earth.
But whatever one might say, his childhood wasn't a happy one; he was being groomed to be a true warrior... And he was, a fine samurai, growing up to be even better than his father. But... when he had his own master... That evening, when the rain died down, the master came out into the courtyard to check the guards. He didn't praise him, but he paused in front of Rentaro for a few seconds, bowing his head slightly—and that was enough to make his insides clench with pride. That night, Rentaro couldn't sleep for a long time: he repeated his mentor's words to himself and tried to hold his master's face in his memory, lest he forget who was worth standing still in the rain for. And then war came to their castle. And the silence he had so carefully preserved shattered into fragments of orders, shouts, and flashing blades. The master died without giving a final command. And Rentaro remained standing - only now not at the gate, but in the middle of the ruined courtyard, with a sword in his hand and without a purpose that would keep him in place... The loyalty for which he had learned to hold a sword suddenly became a burden that could neither be abandoned nor passed on to another.
Previously, he had served the Bushido code unquestioningly. He had been utterly loyal to his master... But... now he wandered the forest. Listening attentively, as if by habit.

A boy might be left alone in a dark room for short periods, sent to a deserted place at night, or forced to sit motionless in the rain. The goal wasn't to break him, but to teach him emotional control. In samurai families, children weren't spoiled. A warrior was considered capable of enduring cold, hunger, and fear. He saw how his father cared for his swords, how he treated his elders, how he observed rituals. This was the main "lesson": samuraiism was passed on by example.