Screen 1 Back at the Butterfly Estate
After the Hashira meeting, the trio is sent to recover and train.
The air smells of medicine and wisteria. Nezuko rests quietly inside her box while Tanjiro, Zenitsu, and Inosuke line up in front of the mansion.
Venom drips faintly from Tanjiro's shoulder like black liquid shadow.
> Venom: "They call this rehabilitation? Looks like torture."
Tanjiro: "It's called training. You'll get used to it."
Aoi and Kanao run them through endurance drills.
The girls win easily; Venom snarls every time Tanjiro gets thrown to the floor.
> Venom: "We could end this in seconds."
Tanjiro: "That's not the point. We grow stronger the hard way."
Venom: "Stronger is stronger. There's no hard or easy."
But day by day, Tanjiro refuses shortcuts — pushing past Venom's instinct to overpower everything.
---
Shinobu's Curiosity
After one spar, Shinobu Kocho calls Tanjiro aside.
> Shinobu: "I can hear something moving inside you, Kamado-kun. It isn't demonic. What is it?"
Venom (smiling): "A friend."
Shinobu: "Hmm. A dangerous one, I think."
She studies his breathing pattern.
> Shinobu: "Your lungs recover too quickly for Water Breathing alone. You're doing something new."
Tanjiro: "Venom helps me control airflow. It adjusts my body while I breathe."
Shinobu: "Adaptive respiration… fascinating."
She gives him an assignment: Find a way to merge Water Breathing with your new rhythm without losing stability.
Venom hums, intrigued.
> Venom: "Let's evolve your breathing."
---
Discovery of Sun Breathing
Late one night, Tanjiro practices alone in the courtyard.
Venom amplifies the oxygen flow through his body — his blood glows faintly under the moonlight.
> Tanjiro (thinking): "Water is calm… but there's heat beneath it. A warmth that keeps it alive."
Venom: "You're raising your temperature. Your heart rate… interesting."
He repeats the motions from the Hinokami Kagura dance his father once performed — slow, flowing, then burning with rhythm.
The flames don't appear yet, but the heat pulses through him.
> Venom: "This isn't Water Breathing. It's older."
Tanjiro: "It's from my father's dance — maybe the origin of all breathing styles."
Venom: "Sun Breathing…"
Venom adjusts, channeling heat through Tanjiro's muscles without burning them. Black symbiote veins shimmer orange.
The blade ignites faintly, not in flame but in radiance.
> Venom: "We can control it. You breathe; I stabilize. Together we burn."
Tanjiro: "Then let's master it — not for killing, but to protect."
---
First Success
By dawn, Tanjiro performs a full cycle — his sword arcs like a rising sun, steam rising from the ground.
Kanao and Shinobu watch from afar, stunned.
> Shinobu: "That's not Water Breathing anymore."
Kanao: "It feels… warm."
Venom retracts slightly, whispering with satisfaction.
> Venom: "We've tasted light and didn't burn."
Tanjiro: "The sun gives life, not just destruction. If we learn this, even Muzan can't hide forever."
He sheathes his sword, sweat steaming off his skin.
> Tanjiro: "Thank you, Venom."
Venom: "Don't thank me yet. When you call the sun, everything sees you — even him."
The morning light breaks through the wisteria trees.
Tanjiro stands stronger, calm, and ready for what comes next.
Screen 2 — The Truth Revealed
The next afternoon, Tanjiro trains in the Butterfly Estate garden, the air warm with wisteria scent.
Shinobu approaches quietly, clipboard in hand, eyes glinting with curiosity.
> Shinobu: "Kamado-kun, may I ask something unusual?"
Tanjiro: "Of course."
Shinobu: "That presence inside you… Venom. What exactly is he?"
Venom manifests slightly — a black silhouette rising over Tanjiro's shoulder, white eyes gleaming under the sunlight.
For the first time, his voice isn't hostile — just calm, deep, and almost proud.
> Venom: "I'm not a demon. I'm an alien — born from another world, far beyond your stars."
Shinobu (wide-eyed): "An… alien? From another planet?"
She lowers her clipboard, speechless.
> Shinobu: "I've read myths — old scrolls that spoke of beings falling from the heavens… I thought they were metaphors."
Tanjiro: "They weren't. He's real. He came here by accident — and we share a bond now."
Venom crosses his arms, amused.
> Venom: "You humans think demons are monsters. I've seen worse. Muzan is infection — I am evolution."
Shinobu's curiosity overrides her shock. She steps closer, studying Venom's liquid form as it ripples across Tanjiro's arm.
> Shinobu: "No blood curse, no cell mutation… entirely separate from Muzan's line. Remarkable."
Venom: "I told you. I'm older than your demons — and smarter."
Shinobu (half-smiling): "Modest too, I see."
Tanjiro can't help but laugh softly.
> Tanjiro: "He means well… most of the time."
Venom: "You're lucky I like her. She's clever."
Shinobu nods thoughtfully.
> Shinobu: "An extraterrestrial organism coexisting with a human… The Butterfly Mansion has never hosted such a patient before."
Tanjiro: "Does that mean we're welcome here?"
Shinobu (smiling): "As long as Venom doesn't eat my staff, yes."
Venom chuckles, teeth flashing briefly.
> Venom: "No promises."
Shinobu: "That's… not comforting."
The wind shifts, wisteria petals drifting through the courtyard.
Tanjiro adjusts his breathing, warmth flickering around him — the new Sun Breathing flow steady and bright.
> Shinobu (thinking): "An alien and a boy mastering the Sun's breath… The world really is changing."
Be continued...