Taisho Era – Year 4 (1915)
Location: Kanda Shrine, Tokyo
The Kanda Festival was a sea of light. Thousands of paper lanterns swayed in the evening breeze, turning the temple grounds into a golden dreamscape. The air was thick with the scent of savory takoyaki, sweet plum wine, and the sharp, ozonic smell of early summer rain that never quite fell.
Kai, now seven years old, walked through the crowd with the deliberate poise of a young lord. His burgundy hair was tied back with a new silk cord, and his garnet eyes scanned the surroundings with a rhythmic precision that the "Great Sage" coordinated in the back of his mind. At his side, Mitsuri—also seven—was a whirlwind of emerald and pink, her eyes wide as she clutched a giant stick of candied hawthorn.
"Kai-kun, Kai-kun! Look at the masks!" Mitsuri chirped, pointing toward a stall. "That one looks like a grumpy fox. It reminds me of the old man who sold us those bitter herbs!"
"Careful, Mitsuri-chan," Kai laughed, his voice smooth and playful. "If you eat any more sugar, you'll be able to run all the way to Mount Fuji before the fireworks start."
"Then you'll just have to catch me!" she teased, bumping her shoulder against his. Even at seven, her strength was immense; the casual bump would have sent an ordinary boy sprawling. Kai didn't move an inch, his center of gravity as immovable as a mountain.
'Great Sage, status report on the crowd.'
[Notice: Multiple high-density muscle signatures detected 30 meters ahead. Analysis: Two female subjects. Subject A: 10 years old, moving with "Flower-like" grace. Subject B: 6 years old, heartbeat fast and sharp. Both possess the scent of wisteria.]
Kai's heart skipped a beat. Wisteria. The calling card of the Demon Slayer Corps.
He looked ahead and saw them. Standing near a fortune-telling booth were two girls who looked like they had stepped out of a painting. The elder, Kanae Kocho, was ten years old—three years older than them—and already possessed a hauntingly ethereal beauty. Her long black hair was pinned with two butterfly clips, and her smile was as soft as a spring morning. Beside her stood a six-year-old Shinobu, looking much grumpier, her smaller butterfly clip slightly askew as she struggled with a fan.
"Oh! Look at their hair clips!" Mitsuri gasped, her "wifu-radar" (as Kai internally called it) pinging instantly. "They're so pretty! Kai-kun, can we go say hello?"
"Of course," Kai replied, his mind already spinning. 'Kanae is only ten. She hasn't become a Hashira yet, but she's clearly already training. And Shinobu... she still has her original personality. She hasn't started mimicking Kanae's smile yet because Kanae is still alive.'
The thought sent a jolt of resolve through him. 'I will not let that smile be a mask for grief. Not this time.'
As they approached, Kanae noticed them first. Her violet eyes widened slightly as they landed on Kai. She saw his burgundy hair, his calm stance, and the sheer presence he radiated—something that felt strangely similar to the high-ranking swordsmen she had seen at the Corps headquarters.
"Excuse me!" Mitsuri said, beaming at them. "Your butterfly clips are so beautiful! Did you make them?"
Kanae blinked, then gave a radiant, genuine smile. "Why, thank you, little flower! Our mother gave them to us. I'm Kanae, and this is my sister, Shinobu."
Shinobu looked up, her purple eyes narrowing as she looked at Kai. Unlike her sister's gentle appraisal, Shinobu's gaze was clinical. "You," she said, pointing a small finger at Kai. "Why are your feet so quiet? Even when you walk on the gravel, I can barely hear you."
Kai chuckled, giving a polite, slightly flirtatious bow. "A gentleman shouldn't make a racket when he's escorting a lady as bright as Mitsuri-chan. I'm Kai. It's a pleasure to meet the most beautiful butterflies in Tokyo."
Shinobu's face turned pink. "Don't be weird! You're just a kid!"
"And you're a year younger than me, little butterfly," Kai teased, his garnet eyes shimmering with mischief.
Kanae laughed, covering her mouth with her hand. "My, such a bold boy! You have a very interesting 'color' about you, Kai-kun. And your friend... she has the strongest heartbeat I've ever heard in a child."
Mitsuri tilted her head. "My heartbeat? Is it loud? I just ate a lot of candy..."
"It's not just the candy," Kanae said softly, her gaze turning knowing. She reached out and gently patted Mitsuri's cheek. "You are very special, little one. You have a gift for protecting others."
'She sees it,' Kai thought. 'The Hashira potential.'
"We're both learning how to use our gifts," Kai said, his voice dropping into a more serious tone that caught Kanae's attention. "The world is getting darker. Even in a place as bright as this festival, the shadows are long."
Kanae's smile didn't falter, but her eyes sharpened. "You speak with a lot of weight for a seven-year-old, Kai-kun. Who taught you about the shadows?"
"The shadows taught me," Kai replied enigmatically. He stepped closer to Kanae, lowering his voice so the younger girls wouldn't hear. "Take care of your sister, Kanae-san. Butterflies are beautiful, but their wings are fragile in a storm. If you ever find yourself in a storm you can't fly out of... look for the boy with the sun in his eyes."
Kanae stared at him, a chill running down her spine. It wasn't a threat; it was a prophecy. Before she could ask him what he meant, a loud BOOM echoed through the sky.
The first firework exploded—a massive chrysanthemum of crimson and gold.
"The fireworks!" Mitsuri squealed, grabbing Kai's hand. "Look, Shinobu-chan! It's like a giant flower in the sky!"
Shinobu, momentarily forgetting her suspicion, looked up in awe. "It's... it's huge."
For a few minutes, the four children stood together, bathed in the flickering light of the pyrotechnics. To any observer, they were just two pairs of siblings enjoying the festival. But in the tapestry of fate, this was the first meeting of the pillars that would eventually hold up the world.
As the finale began—a cascade of white light that turned night into day—Kai looked at the three girls. Mitsuri, his future; Kanae, a life he would save; and Shinobu, a soul he would keep from breaking.
"We have to go, Shinobu," Kanae said as the smoke cleared. "Our 'guards' will be looking for us."
"Wait!" Mitsuri reached into her sleeve and pulled out two small charms she had bought earlier—a pair of pink bells. "Here! So we can find each other again!"
She pressed them into Kanae and Shinobu's hands.
Kanae looked touched. "Thank you, Mitsuri-chan. We'll cherish them." She then looked at Kai, her expression deeply curious. "I have a feeling we'll meet again, Kai-kun. Perhaps at a place where the wisteria never withers?"
"I'll be there," Kai promised. "And I'll bring better snacks next time."
As the Kocho sisters disappeared into the crowd, Shinobu looked back one last time, her eyes lingering on the boy with the burgundy hair.
"Kai-kun?" Mitsuri asked, leaning her head against his arm as they watched the last embers fall. "Why did you look so sad when you talked to the tall sister?"
Kai squeezed her hand, his resolve hardening like Nichirin steel.
"I wasn't sad, Mitsuri. I was just making a promise to the future."
'Great Sage,' Kai thought as he led Mitsuri back toward the merchant district. 'Calculate the timeline for Kanae's encounter with Upper Rank Two. How many years do I have to perfect the Sun Breathing forms?'
[Calculation: Approximately 7 to 9 years. Current progress: 22%. Recommendation: Increase intensity of "Hekira no Ten" (Blue Heaven) training. Your physique is ready for the next stage.]
'Then let's get to work,' Kai thought, a smirk playing on his lips. 'I've got a butterfly's fate to rewrite.'