No one told Tanjiro the answer, not even Tanjuro could provide it.
He only knew that the Dance of the Fire God was passed down from their ancestors, and as long as he was willing, he could dance persistently all night.
Yet he didn't understand the principles, but Roy could see clearly through "Gyo" —
It was "Sun Breathing" that granted Tanjuro strength.
Helping him resist the cold and maintain his stamina.
Unfortunately, Tanjuro didn't know how to utilize this power, or perhaps... his frail body simply couldn't withstand the immense strength.
Even if Roy told him how to use it, he would die on the spot, unable to withstand the burning of the Power of the Sun.
Once... twice... three times... five times... six times...
The fluttering sleeves stirred the flying snow, and Tanjiro could no longer keep up, sitting down on the ground.
On a snowy night, only Tanjuro and Roy continued dancing.
From the initial clumsy awkwardness to barely keeping up, then to smooth and fluid movements without any stiffness, Roy became increasingly adept, eventually matching Tanjuro's rhythm.
Tanjuro noticed his movements, initially surprised, then deliberately speeding up to test him, a smile slowly spreading across his lips....
From time to time, a thought would emerge in his mind: 'If Eiichiro Oda's grandfather could see this, he would surely be astonished at his talent for learning the Dance of the Fire God...'
Sadly, the ancestors have passed away, and Eiichiro's grandfather was destined never to see this... and Tanjuro also had a premonition that soon he too would descend....
"Whoosh...."
A gust of wind blew, stirring Tanjuro's thoughts....
Snowflakes fell through the helmet onto Tanjuro's face.
The man felt comforted yet melancholy, and upon coming back to his senses, his heart was filled with guilt and regret...
His mother was old and couldn't work.
He had contracted tuberculosis in his early years and couldn't do heavy labor.
In recent years, a few more children had been added to the family, all dependent on Kie Kamado.
Next, the burden of the entire family would fall on Roy's shoulders.
But as a father, all he seemed to be able to do now was pray...
'Then pray earnestly....'
'Pray...'
'Lord Fire God, please bless Eiichiro and the children with health, peace, and safety....."
With a flick of his long sleeve, Tanjuro danced seriously, stopping only at the eighth repetition.
A corner of the flaming face helmet lifted, revealing his pale, sickly face.
Roy followed closely, albeit half a beat slower, stopping reluctantly and assisting Tanjuro back...
Tanjuro patted his hand, sat back against the porch pillar.
A few children cheered and gathered around, chattering incessantly.
Some praised how beautifully Tanjuro danced, others praised Roy's prowess, while some teased Tanjiro for being clumsy like a toad.
Tanjiro wasn't angry either, instead grabbing the teasing Takeo's top hair tuft, but Takeo dodged, hiding behind Roy.
"Brother Eiichiro, Tanjiro is just too dumb~" Takeo jeered.
"Call him Brother Tanjiro."
Roy lightly tapped Takeo's little noggin with a hand blade, giving him a playful glare before sitting down to recall his previous actions.
A family knows its own affairs, children only see the surface, not the facts.
Roy knew it wasn't that he was smarter than Tanjiro.
On the contrary, he had an initial advantage, firstly, he could use "Gyo" to analyze Tanjuro's movements more clearly than Tanjiro.
Secondly, thanks to the Zoldyck Family's hellish training, his physical strength was far beyond Tanjiro's, making it naturally faster to imitate.
Moreover, Tanjiro was destined to learn "Sun Breathing."
But he still needed to undergo the most crucial test — enduring the "Weight of the Sun"!
Withstanding it would allow him to fully master "Sun Breathing," failing would lead to disappointment.
The young man calmed his mind, neither sad nor joyful. After contemplating for a while, he got up and went into the kitchen, and soon returned with two plates of dumplings... white rice wrapped in vinegar cloth with a drizzle of sauce, which was tonight's full moon festival dinner.
Of course, along with the miso soup served by Kie Kamado.
There was a chunk of rib in the soup, so simple that Roy was a bit dazed....
Since being born in the Zoldyck Family, he had never eaten so simplistically, let alone had only fish and meat because of his training, his family would also provide medicinal supplements.
Looking at Tanjuro's condition now, and then at Kie Kamado, grandmother, and the kids' complexions... Roy then deeply understood—
In an era rampant with Evil Ghosts, just living itself was a luxury.
And even, two years later, except for Tanjiro and Nezuko, all these lively faces seen now would ultimately disappear.
This... was not something Roy wished to see.
'Recompense the grace received, since I have learned "Sun Breathing," I should give back later.'
'At least, they should be able to eat meat.'
Roy had made up his mind, and when Kie smiled and said dinner was ready... he clasped his hands together, picked up the bowls and chopsticks....
Amidst the night, he ate heartily and soon finished the meal.
After accompanying Kie to tidy up the remnants and coaxing the little ones to sleep, he removed his shoes and socks, found his bedding, laid down, and let off the fatigue of the day.
By this time, the night was deep, yet the snow made it as bright as day.
Roy, Tanjiro, Takeo, Mao, and a few kids slept on a large shared bed.
With his eyes closed, he could occasionally hear Takeo grinding his teeth and Mao's slight farting...
The sounds and smells were so real that Roy began pondering whether, after this sleep, he would truly leave this place and return to the real world.
Looking to his side, Tanjiro couldn't sleep, tossing and turning like a salted fish, finally having to widen his amber eyes and quietly wriggle to Roy's side and ask: "Brother, are you asleep?"
"Brother" was Tanjiro's unique way of addressing him, with the other kids including Nezuko calling "Brother Eiichiro."
Roy lied with his eyes closed: "Asleep."
Tanjiro: "..."
"Oh~", he pulled the quilt over his face and lay flat.
Roy knew what he wanted to say.
Tanjiro also knew Roy didn't want to talk now.
In fact, what he didn't know was that... Roy just hadn't thought of a suitable explanation.
After all, he, as Brother Eiichiro, was also encountering the Gate of Cognition and this world for the first time, wasn't he?
'So, my silly Mamen Beans, please give me a little more time....
'Just a little...'
Roy thought to himself, gradually calming down.
As he drifted into a dream.
Until—
"Awoo!"
A familiar dog bark woke him.
The barking belonged to the beast kept by the Zoldyck Family, mainly responsible for eating intruders and — the crowing Mikai.
That's right, it was 3:50 AM when Roy woke up.
He turned over and sat up in bed.
Seeing the clock in the corner of the room, along with the familiar desk and wardrobe... he knew he had left the world of Demon Slayer and returned to the Zoldyck Family.
Just a moment ago, he was huddled in that simple little wooden house braving the cold, but in a flash, he was back in a solemn mansion enduring the heat... Was it Zhuang Zhou's dream of a butterfly, or a butterfly dreaming of Zhuang Zhou?
Roy stared blankly for a while, lost in deep thought....