Sensei Yazuko stood at the front of his dojo, silently scrutinising his two best students - two boys he considered his sons. Kai and Takeshi.

Life was peaceful for their small family. Since both their returns from mainland Japan from the camp, the two were more determined than ever. They had settled into their own rhythm, Sensei Yazuko's days consisted of training Kai and Takeshi as well as other students and cooking meals.

The routine they lived in was broken one day when he sensed a figure at the door of his dojo. He turned his head and was momentarily stunned.

It was a woman, not one he had ever met but he still recognised her instantly. She walked with a measured precision, her gaze piercing as she approached Sensei Yazuko. They exchanged a brief bow before the woman straightened, speaking to him in Korean.

"Sensei Yazuko, I am Kim Da-Eun."

Yazuko understood what she was saying, he had picked up basic Korean in his past. He looked at her, inspecting her from bottom to top. The name brought back a rush of memories he had long forgotten.

He knew who she was. Not even as the granddaughter of Kim Sun-Yung, a master in Korean Tang Soo Do but as someone else. Her presence was enough to make him stiffen as he realised there was an ulterior motive to her visit.

"You've travelled far. This must be of great importance." Yazuko's tone was guarded but respectful.

He wondered how she knew of him, perhaps after years of digging she tracked him down.

"I come on behalf of a powerful man. He is calling on the finest Senseis in the world to join him, to build something formidable under Cobra Kai."

Yazuko's face tightened at the mention of Cobra Kai. He'd heard rumours of Terry Silver, the wealthy American who had resurrected Cobra Kai's teachings with an approach that seemed to thrive on aggression. After all, he was trained by Kim Sun-Yung himself.

This filled Sensei Yazuko with initial doubt. Although similar in karate styles, the values Cobra Kai currently stood for did not align with Yazuko's nor Tiger Claw's.

"Cobra Kai stands for dishonour. They teach their students that mercy is weakness, that strength comes through domination. I do not agree with that path."

Kim's face remained impassive, but there was a flicker of impatience in her eyes. "I know that it may not align with your philosophy, but I did not come here to discuss personal beliefs. I came to ask you to fulfil an obligation - a debt owed to my family."

Yazuko's jaw tightened. He knew of the debt, the unspoken duty he owed to her family that lingered like an old wound. He had hoped that, with time, it would fade, that he might be allowed to honour it in his own way. But here she was, Kim Da-Eun herself, reminding him that honour could not be deferred.

The memory always began with the faint hum of cicadas, their low, droning song weaving through the muggy South Korean air. Sensei Yazuko, no older than sixteen, had been stationed in the rugged countryside, the forested hills around him cloaking the shadows that stretched far past sundown. The Japanese army had sent him to aid with logistics, a routine assignment far from the battlefield, and yet he had been thrust into a conflict he could neither escape nor control.

It was a late summer evening, the sun slipping beyond the hills as the air thickened, heavy with tension. He had been sent on an errand - a simple enough task, to deliver some supplies to a nearby station. But as he trekked through the dense undergrowth, he sensed that something was wrong. An eerie silence settled over the forest, replacing the usual birdsong with a hollow stillness. He felt exposed, his uniform clinging to him, his rifle a weight that felt foreign in his trembling hands.

As he neared a clearing, the ambush struck.

It happened too quickly to comprehend. Gunfire erupted, tearing through the trees as figures emerged from the shadows, their faces painted with cold determination. Yazuko had barely raised his rifle before he found himself face down in the dirt, his heart pounding wildly as bullets whizzed past him, tearing through the thick undergrowth. He was alone, outnumbered, and completely unprepared for combat.

He tried to move, but his body was frozen, paralysed by fear and the sickening realisation that he might not make it out alive.

He couldn't die. He wasn't ready to die. He was just a kid. He hadn't had his first kiss, he hadn't gotten married, he hadn't started a family. And now his life was this close to ending.

Then, through the smoke and gunfire, a figure emerged - a man, older and calmer than any soldier Yazuko had ever seen. His uniform marked him as South Korean military and he locked eyes with the younger soldier, a wave of guilt and sympathy in his eyes.

Yazuko tried to scramble back, but the man held up a hand, signalling him to stay quiet. He could see it now: this was no enemy. The man spoke in halting Korean, his voice low and filled with a quiet urgency.

"Are you alone?"

Yazuko managed a faint nod, his throat too tight to form words.

The man's gaze softened, and he stepped closer, crouching beside Yazuko as bullets continued to fly around them. He glanced over his shoulder, scanning the forest with the precision of someone who had seen too many battles, who understood that survival was as much a matter of strategy as it was of luck. He motioned for Yazuko to follow, his movements swift and silent.

As they crept through the trees, Yazuko tried to steady his breath, his heart pounding in time with each step. The man moved with a grace that belied his age, his hand guiding Yazuko forward, pushing him when he stumbled, always one step ahead. Yazuko felt an overwhelming gratitude mixed with a deepening dread, for he knew that this stranger was risking everything to help him - an enemy no less.

They reached a small ridge, and the older soldier pulled Yazuko down, pressing him against the earth as he scanned the area. His face was tense, a line of sweat tracing his brow, but his eyes held a calm resolve.

"You're just a boy," he murmured, almost to himself, "you don't belong in this."

Yazuko swallowed hard, feeling the weight of those words settle over him. He didn't belong here; he knew that, had known it from the moment he'd set foot on foreign soil. But there was no escaping his duty, no turning back from the path he'd been forced onto. He looked up at the older soldier, a question forming on his lips, but before he could speak, a shout rang out, echoing through the forest.

The Korean soldier's face hardened, his gaze flickering to the ridge below where a group of soldiers had gathered, scanning the area. They were closing in fast and Yazuko felt a surge of panic, but the older man's hand gripped his shoulder, grounding him.

"Stay low," he whispered, his voice firm, "no matter what happens, do not move."

Yazuko nodded, his throat tight as he watched the other soldier stand, his posture tall and unwavering. Kim took a step forward, drawing the soldiers' attention, his hands held up in a gesture of surrender. Yazuko wanted to scream, to pull him back, to stop him from sacrificing himself for a boy he barely knew. But he was paralysed, his body rooted to the ground as he watched him walk into the line of fire.

The soldiers shouted, not recognising him as one of their own. In the spur of the moment, they assumed their ally to be an enemy and unleashed a barrel of shots. Yazuko realised what was happening, the older soldier was trying to buy him time - drawing their attention. But his plan had failed, his comrades - in the spur of the moment - mistook him for the enemy and shot him.

As the Korean soldier fell to the ground, he turned his head, meeting Yazuko's gaze one last time. In that brief moment, Yazuko saw a depth of kindness and strength that he would never forget.

And then those eyes became lifeless.

Yazuko felt a scream rise in his throat, but he choked it back, clenching his fists as he forced himself to stay still and to make sure the soldier did not die in vain. He waited, his body trembling, until the soldiers had moved on, finally realising their actions and carrying their fallen comrade back with them.

Yazuko never spoke of that day to anyone. He carried the memory in his heart, a silent vow etched into his soul, a debt that could never truly be repaid. He returned to Japan, haunted by the image of the stranger's final moments, the selflessness of a man who had seen a scared boy and chose to save him, to give him a second chance at life.

He found out the name of the man who saved his life. Kim Cho-Yang.

Years later, Yazuko tried to put his past in the past but the weight of his debt lingered, a constant reminder of the man who had given everything for him. He had always known that one day, he would be called upon to repay that debt.

When Kim Da-Eun, the daughter of the man who had saved his life, appeared at his dojo, he felt that debt rising, like a ghost returning from the shadows.

Now, as she stood before him, reminding him of his obligation, Yazuko knew that he could not refuse her. He saw in her eyes the same determination he had seen in her father's. And though it pained him to align himself with Cobra Kai, to bring his students into a world of aggression and ruthlessness, he knew that he could not deny the honour he owed her family.

With a deep bow, he looked up at her, his voice steady.

"I will go with you, Sensei Kim. And I will bring my students. For your father, I will honour my debt."

Kim Da-Eun inclined her head, her gaze softening, a flicker of respect passing between them.

"Thank you, Sensei Yazuko," she said, her voice low and filled with a gratitude that ran deeper than words, "my father would be proud."

Yazuko's thoughts flickered to Kai and Takeshi, his dojo's most promising young fighters. Kai's strength and Takeshi's discipline were forged in Tiger Claw's ethos, shaped by a dedication to a higher path. They had been taught the importance of restraint and control, the balance of power and humility. The thought of throwing them into the world of Cobra Kai, into an arena that prided itself on dominance and ruthlessness, struck him as wrong. And yet, he knew the honour he owed Sensei Kim's family.

"I will bring my students. But know this, Sensei Kim - I will not let their spirit be broken. If this Terry Silver strays too far from the path of honour, I will take my students and leave."

Sensei Kim nodded and said nothing else. It was settled.

Kai Hilton was coming back to America.

Again.