Down a narrow country road, Rengoku and his companions were moving at a speed no ordinary person could match.
As the Flame Hashira, Rengoku could sprint fast enough to chase down a running train.
Chika, whose physique far exceeded that of an average human, wasn't far behind.
When she didn't bother conserving stamina, her basic physical stats were second only to Gyōmei Himejima, the Stone Hashira—so keeping pace with Rengoku was no problem at all.
Tanjiro and Nezuko lagged slightly behind, but not enough to be left out of sight.
Both ran hard, staying only about ten meters behind the lead pair.
"Chika," Rengoku called out while running, his voice steady despite the wind, "when we reach my home, you'll likely meet my father. He hasn't been well since my mother passed away. If he says something offensive, please forgive him."
Rengoku's father—Rengoku Shinjurō.
The former Flame Hashira.
He had once been a good-natured man, cheerful and loud like his son.
Even the current Serpent Hashira had once been saved by him.
But that was long ago.
During one of his missions away from home, his wife had fallen ill.
Her health was fragile to begin with, and by the time he returned, she was already gone.
The loss shattered him.
The balance between his duty as a husband and his mission as a Hashira collapsed completely.
Blaming himself, Shinjurō resigned from the Corps, drowned himself in alcohol, and shut out the world.
He became a man who feared losing anyone again—so he drank to numb his heart.
Even his beloved sons could no longer reach him.
When Kyōjurō was appointed the new Flame Hashira, his father didn't even attend the ceremony.
"What a miserable fate," Chika muttered softly, almost without realizing it.
The wind carried her words away, but Rengoku glanced at her in confusion.
He hadn't quite caught it.
Chika quickly waved it off, flustered. "Ah, it's nothing. We're almost there, right?"
"Mm. Just another two or three kilometers."
To them, that was practically "right around the corner."
Within minutes, they arrived at the gates of the Rengoku Estate.
Outside the gate, a boy who looked nearly identical to Rengoku was sweeping the path.
"Senjurō!" Rengoku called out warmly.
The boy turned, eyes lighting up.
"Big brother!"
He ran straight into Rengoku's arms, grinning from ear to ear.
This was Rengoku Senjurō, Kyōjurō's younger brother.
He lacked the talent for Breathing Techniques—no matter how long he trained, his Nichirin Blade had never changed color—so he remained at home, tending to chores.
Seeing his brother return made him genuinely happy.
Rengoku patted his head, smiling, then gestured toward the guests.
"Senjurō, we have visitors. This young lady is Chika, the brightest new star of the Demon Slayer Corps—she single-handedly defeated a Lower Rank demon not long ago.
And these two behind her are her younger siblings. They came to look through our family's records, so I brought them along."
He paused. "Is Father home?"
And as if summoned by the question, a rough voice echoed from within the house.
"What's with all the noise? Kyōjurō… you're still alive, huh?"
Out stepped a man clutching a sake bottle in one hand. His unshaven face and dull, lifeless eyes carried the look of someone who'd given up on the world.
Even Chika couldn't help mentally saluting him.
To reach this level of 'dead-fish eyes'—that's mastery. True endgame sloth.
Alas, I haven't even reached intermediate slacker-tier yet…
Rengoku, however, didn't seem fazed at all.
"Hahaha! Of course I am! There are still so many demons out there. I won't die so easily, Father!"
For a brief moment, Shinjurō looked at his son—the spitting image of his younger self—and clicked his tongue quietly.
Then his eyes caught something else.
The earrings.
Hanging from Tanjiro's ears were a pair of distinctive Hanafuda earrings.
Shinjurō's pupils shrank.
Rengoku didn't know their meaning.
Senjurō didn't know either.
Even Chika, for all her knowledge of the story, felt a chill at the way Shinjurō's expression changed.
The Breath of the Sun.
The first and strongest Breathing Style.
A technique said to belong only to those chosen by fate.
All other Breathing Styles—Flame, Water, Wind, and the rest—were but pale reflections of its original brilliance.
And in Shinjurō's eyes, that brilliance ignited something dark.
Anger. Bitterness. Grief. Envy.
Before he even realized it, his body had moved.
"Father!"
In a flash, Shinjurō lunged toward Tanjiro, his speed startlingly fast for someone supposedly drowned in drink.
Tanjiro sensed danger and instinctively stepped back, but not fast enough—Shinjurō's hand was already inches away from his face.
But then—
Clack!
Rengoku's strong arm clamped down on his father's shoulder from behind.
And before the strike could land, Chika's hand shot out, gripping Shinjurō's wrist like an iron vice.
"Rengoku-san's father," she said firmly, her eyes sharp. "Please calm yourself."
It was instinct.
Shinjurō had moved without thinking.
And so had she—especially since this man had dared raise a hand toward her little brother.
In her mind: Sir, you must be joking.
Pinned by both Rengoku and Chika, Shinjurō's fury gradually subsided.
He exhaled heavily, though his eyes still burned with turmoil.
When he finally spoke, his words came out rough, but clear.
"Don't get arrogant. Don't grow complacent. Even the creator of the Breath of the Sun couldn't defeat the Demon King.
And you… you couldn't even react properly to my movements. You're still far too weak!"
With that, he shook free of their grips and turned away, retreating back into the house, the faint clink of his sake bottle echoing behind him.
Tanjiro stood frozen, stunned by both the speed and the venom in those words.
While, Chika sighed quietly.