The afternoon sun hung low over the bustling streets of Paras City, painting long golden streaks across the cracked stone footpath. Sai walked with his usual lazy stride, hands buried deep in the pockets of his worn black coat, the hem fluttering slightly with each step. The noise of merchants haggling, children laughing, and distant carts rumbling washed over him like background static—he barely registered any of it.
Then it hit.
A single, sharp memory pierced through the haze in his mind like a needle. His footsteps faltered. His body froze mid-stride.
His blue eyes—usually calm, almost bored—widened for a fraction of a second. The pupils trembled.
"…Father?"
The word slipped out unconsciously, so quiet even the wind couldn't carry it.
And just like that, the world around him blurred and dissolved.
---
**Flashback — North Lake Village, Many Years Ago**
The wooden sliding door of the dojo burst open with childish force.
A small boy—no older than seven—leaped out into the sunlight, black hair messy, kimono slightly askew, cheeks puffed in exaggerated frustration.
"Father!!"
Yamato, younger then, hair still mostly dark with only the faintest threads of silver at the temples, turned from where he was sweeping the stone path. The broom paused mid-swing.
Sai skidded to a stop in front of him, fists clenched at his sides.
"I'm boooored! I want someone to play with me! Right now!"
Yamato's stern expression melted into something softer. He crouched down, resting one large hand gently on the boy's head.
"My child," he said quietly, voice warm like lake water in summer, "don't worry. Other kids will play with you soon."
Sai's pout deepened. He spun on his heel, scanning the open area near the dojo.
"Who will?"
A group of village children stood clustered near the cherry trees. The moment Sai's gaze landed on them, they flinched—like startled deer. One by one they shrank back, hiding behind trunks and each other.
A woman—someone's mother—hurried forward and pulled her little girl behind her skirt. Her voice came out sharp and trembling.
"M-Monster… Don't look at my child like that!"
The word struck Sai like a slap he didn't understand.
He turned slowly back to Yamato, big blue eyes glistening, confused and hurt.
"…Father? Why are they running away from me?"
Yamato's jaw tightened for only a heartbeat before he forced a gentle smile. He reached out and straightened the collar of Sai's kimono.
"I guess… they just don't want to play right now. It's okay. Let's not mind them."
He took Sai's small hand in his own calloused one.
"Come. Let's find someone who will."
They walked together toward the flower garden behind the dojo.
And there she was.
A girl about Sai's age sat cross-legged among blooming lotuses, weaving a tiny crown of white petals. When she heard footsteps she tilted her head, long dark hair sliding over one shoulder like silk.
Her eyes lit up the moment she saw him.
"Sai? You're here?"
Sai pointed excitedly. "Suro-chan! She's in my school!"
Yamato chuckled, the sound low and fond. "So you already know her?"
Sai nodded so hard his bangs bounced. "She plays with me during lunch! She's my friend!"
He released Yamato's hand and ran forward without hesitation.
"Suro-chan! Can we play?"
Suro sprang to her feet, petals fluttering around her like snow. She nodded vigorously, cheeks already pink.
"Sure!"
Sai grinned—bright, unguarded, the kind of smile he almost never wore anymore.
"Okay! I'll count! You hide!"
He pressed his forehead against the rough bark of an old sakura tree, squeezed his eyes shut, and began.
"One… two… three…"
Suro darted behind a thick cluster of hydrangea bushes. A few other children who had been watching from a distance crept closer, hesitant.
"Is… is it safe?" one boy whispered.
Another tugged his sleeve. "We wanna join too…"
Suro peeked out and waved enthusiastically. "It's okay! Come play! Sai's really nice!"
The fear in their eyes softened. One by one they smiled, then ran to find hiding spots.
Sai finished counting.
"Ready or not—here I come!"
He opened his eyes.
And in that instant, the world sharpened.
Through the leaves, through the shadows, through distance itself—every hiding place glowed crystal clear to him. Heat signatures. Breathing patterns. Even the nervous twitch of a foot.
His special eyes.
One by one he found them. A giggle here. A squeak there. A playful shout when he tagged someone's shoulder.
Finally he reached the hydrangeas.
"Found you, Suro-chan."
Suro popped out, cheeks puffed, arms crossed. "That's cheating!"
Sai tilted his head innocently. "It isn't."
"It is!"
The other kids burst into laughter. One boy dramatically flopped backward into the flowers, arms spread like he'd been defeated in an epic battle.
From a distance, Yamato watched with quiet pride, arms folded.
Until two tall figures in dark blue hakama emerged from the dojo's shadowed entrance.
They strode straight toward Sai.
Before Yamato could react, rough hands seized the boy's thin arms.
Sai blinked up in confusion. "Huh…?"
Yamato's broom clattered to the ground.
One of the seniors—face hard, eyes cold—growled, "Training time, little weapon. Let's go."
The other one smirked. "We've got strong monsters waiting. No time for games."
Sai's pupils shrank to pinpricks.
"B-But… I was playing with Suro-chan… and school tomorrow…"
The seniors laughed—harsh, grating sounds.
Yamato stepped forward, voice low but shaking with restrained fury.
"You can't just drag my son away like some training dummy. He has school. He's still a child."
The first senior sneered. "Old man, shut your mouth. School? Playing? None of that matters. He's the clan's strongest. That's all he is."
They yanked Sai harder.
"Wait—!" Sai's voice cracked. "Don't insult my father! It's not his fault!"
Suro ran forward without thinking, grabbing Sai's other hand.
"Sai… don't go!"
One of the seniors shoved her—hard.
She stumbled back, falling onto the grass with a small cry.
Yamato's hands clenched into fists. Tears gathered at the corners of his eyes, but he couldn't move. Couldn't stop them.
"So this…" he whispered, voice breaking, "…is the price of being the strongest."
They dragged Sai away.
His small body twisted, looking back helplessly at Suro's tear-streaked face, at his father's trembling shoulders.
---
**Training Grounds — Days That Became Years**
Endless.
Weight upon weight strapped to his limbs until his knees buckled.
Punching bags until his knuckles split and bled.
Carrying boulders bigger than himself up endless stone steps.
Water techniques forced out of him until his arms shook and his vision blurred.
And always the same shouts.
"Faster!"
"Harder!"
"You're the pride of the Water Clan! Don't shame us!"
Sai fell to his knees again and again.
An elder loomed over him.
"Why have you stopped? Keep going."
A sharp slap across the back of his head.
Tears dripped onto the dirt.
Sai pushed himself up, voice small and trembling.
"Okay… I'll do it… Please… don't hurt me anymore…"
Night after night he sat alone in a crumbling shack on the edge of the training grounds.
They shoved a bowl of half-cooked potatoes and stale rice at him.
"Eat. Quickly."
He forced it down even as his stomach rebelled. He'd never tasted anything so bitter in his life.
"When… can I go back to school?" he asked once, voice barely a whisper. "When can I see Father… see Suro-chan…?"
The senior only laughed.
"Years. Maybe never. Get used to it, weapon."
Something inside Sai's chest cracked that night.
And it never fully healed.
---
**Years Later — Teen Sai Returns**
The North Lake dojo looked smaller than he remembered.
Yamato sat alone on the engawa, head bowed, silver now threading heavily through his hair. His shoulders sagged under an invisible weight.
Then he felt it.
A presence.
Familiar. Powerful. Cold.
Yamato shot to his feet.
"My kid…?"
Sai stepped into the light.
Older. Taller. Expression blank. Eyes no longer bright with childish wonder.
Yamato's arms opened wide, tears already falling.
"You returned!"
He crushed Sai in a hug.
Sai stood stiff for a long moment… then slowly, hesitantly, raised his arms and returned it.
Suro appeared at the gate, basket of laundry forgotten in her hands.
"Sai…?"
She dropped everything and ran.
"You really came back!"
She threw herself against him, hugging tight.
For a heartbeat, everything felt almost right.
Until the shadow fell across them.
A senior—older now, but no kinder—strode up.
"Enough sentimentality. There's a high-grade beast in the eastern marshes. Expensive. We need it alive. Move, weapon."
Yamato stepped in front, hand already on the hilt of his sword.
"That's enough. You will not take him again."
His voice shook—not from fear. From rage. From grief.
Suro clenched her fists, eyes blazing.
"I won't let you drag him away like this ever again!"
The senior cracked his knuckles, amused.
"Oh? The whole family wants to play hero today?"
He drew his blade. Water energy coiled around it like living serpents.
He lunged.
Suro froze.
Yamato shouted, "Wait—!"
But Sai moved first.
His right hand caught the sword mid-swing.
The blade bit deep into his palm. Blood welled instantly, dripping onto the stones.
His left hand gently pulled Suro behind him, shielding her. Her hair fluttered against his shoulder.
Sai's face fell into shadow.
His eyes glowed—bright, cold azure.
"No more games."
He released the sword.
Suro gasped at the wound, immediately pressing her small hands over it, trying to stop the bleeding.
"Sai… you don't have to do this alone…"
The senior snarled.
"Our weapon dares defy us? Fine."
He raised the blade again.
"Then we'll just have to dispose of the old man and the girl first."
Suro stumbled back, sweat beading on her forehead.
Yamato drew his own sword, stance unsteady but resolute.
The senior slashed at Suro—
Sai caught the blade again. This time with both hands.
The metal screamed.
Cracks spiderwebbed across the steel.
Steam hissed from the fractures.
Sai's voice came out low. Dangerously calm.
"You're a joke."
The sword shattered completely. Shards rained down like broken glass.
The senior threw a desperate punch.
Sai sidestepped without effort—then rose.
He walked on air.
One step. Two.
Floating.
"You crossed a line."
Teleport.
A blazing water-infused spinning kick—twice—slammed into the senior's chest.
The man crashed through three trees, splintering trunks, before smashing into the dojo wall and crumpling.
Sai landed lightly in front of him.
Hands back in his pockets.
Muscles faintly glowing beneath the torn edges of his kimono.
"Stay in your place."
He snapped his fingers.
A perfect sphere of water erupted around the senior, trapping him inside.
"W-Wait—what is this—?!"
The bubble contracted—then detonated.
A massive plume of steam and mist exploded skyward.
Silence.
Yamato stared in horror.
"Sai… what have you done? Killing within the clan is forbidden—!"
Sai didn't look at him.
"When they mocked you. When they attacked you. When they tried to hurt Suro-chan. When they insulted my family… wasn't that against the rules too?"
Suro's eyes softened, tears brimming.
"Sai…"
He turned away.
"I'm leaving."
"Sai—wait!" Yamato called.
Suro ran after him, grabbing his sleeve.
"Don't go! Not like this! Please—we can fix it! We can talk to the elders—"
Sai gently pulled free.
He looked back at Yamato.
"Father… the clan will be safe. Until the day you die."
Yamato's face paled. "Don't… don't speak such blasphemy. You can't destroy our home…"
Sai's expression didn't change.
"Think whatever you want."
Suro stepped forward, hands trembling.
She held out a sheathed katana—beautiful, deep blue wrappings, faint waves etched into the scabbard.
"This… is the Royal Water Katana. I won it in the Grand Water Tournament last year. It's yours now."
Sai hesitated.
Then he took it. Quietly.
"…Thank you."
He turned.
And walked away.
Suro fell to her knees, tears streaming freely.
"Please… come back someday… and don't… don't destroy everything…"
Yamato sank to the ground, head bowed.
"I didn't raise my son… to walk away like this."
---
**Paras City Gate — Present Day**
The memory faded.
The sounds of the city rushed back in.
Sai stood motionless on the footpath, staring down at the katana in his hand.
The once-pristine blade was cracked now. Chipped. The scabbard scarred from countless battles.
He ran his thumb along the fracture.
"Now… this is meaningless."
His grip tightened until his knuckles whitened.
"They let my father die at the hands of that Mermaid Queen Fura… They abandoned him. And when they needed power, they didn't come asking for Sai. They came asking for the strongest weapon."
His eyes narrowed, cold fire flickering in their depths.
"I'm sorry, Father. I'm sorry, Suro-chan."
He exhaled slowly.
Then started walking again.
Forward.
Alone.
"I'll do this myself."
A faint, dangerous smile touched his lips.
"Destruction."