Everything...Can't Go Back

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The "Breath of the Sun" was first created by Tsugikuni Yoriichi, who later shared it with his brother, Tsugikuni Michikatsu, and other members of the Demon Slayer Corps.

However, not everyone could master the Breath of the Sun. Many found themselves unable to withstand the sun's powerful energy that this breath technique required.

Because of this, Yoriichi helped others develop unique breathing styles—kokyuu—based on the Breath of the Sun.

The intense sunlight energy within the Breath of the Sun demanded incredible perseverance and physical resilience, so only a few could endure it. As a result, swordsmen who wielded this breath were rare in the Demon Slayer Corps.

Yet those who mastered the Breath of the Sun held a clear advantage over demons; nearly all who did became pillars of strength within the Corps.

It was this fearsome technique that caught Kibutsuji Muzan's attention, and over time, fewer swordsmen practiced the Breath of the Sun.

Hundreds of years ago, when the Corps' security measures were less advanced, Kibutsuji Muzan discovered their headquarters and launched a deadly attack there himself. To protect their leader and ensure the Corps' survival, all the swordsmen who wielded the Breath of the Sun were killed in that battle.

In the aftermath, the Breath of the Sun's legacy vanished, fading from memory. Over time, its existence was almost entirely forgotten, even by the demons.

At first, Himejima Gyomei didn't connect the technique to the Breath of the Sun. But as the Rock Pillar, privy to much Corps knowledge, he quickly recalled fragments of historical accounts referencing a lost Breathing Style tied to immense power.

Realizing that the technique Ryuji used could align with these records, Gyomei's expression grew serious. Bowing slightly, he asked, "Would you grant me the honor of a conversation with you?"

Ryuji stood with his dagger in hand, silent for a moment. Finally, he nodded. "Of course."

After all, the world he was in was ruled by demons, and if he planned to gain power and attribute points, he'd eventually have to face them. Understanding demons and their ways was essential.

And undoubtedly, the Demon Slayer Corps held the most knowledge about demons.

After their lengthy conversation, Ryuji agreed to share the Breath of the Sun technique with the Corps in exchange for a substantial reward.

However, when Gyomei offered Ryuji a senior position within the Corps, he hesitated, explaining he couldn't make the final decision without consulting their leader.

Ryuji didn't press him, allowing Gyomei time to get approval.

With the topic of Breath of the Sun discussed, Gyomei moved on, questioning Ryuji in detail about the demon he had slain the previous night.

Ryuji answered openly and added information about another demon he had seen lurking nearby. Hearing this, Gyomei's expression grew even graver.

The two came to a shared suspicion that the leaders of Flower Street were likely colluding with demons, a revelation that led to even deeper discussion.

Time flew by, and as the first light of dawn streamed through the windows, Gyomei finally rose.

"I apologize for keeping you up so long," he said, clasping his hands together in slight bow.

"It's no trouble. I learned much from our conversation, Gyomei," Ryuji replied, appreciative. Their conversation had provided Ryuji valuable insights into demons, insights that would undoubtedly prove useful.

"If I may ask, Gyomei, where are you currently staying?"

Ryuji was keen to keep in touch. If he ever needed assistance or faced another powerful demon, he'd know where to find Gyomei.

"We don't have a fixed residence," Gyomei replied. Demon Slayers, he explained, seldom stayed in one place for long.

"In that case, you're welcome to stay at my home for now. It would be my honor."

Gyomei hesitated. "Would that not be an imposition?"

"Not at all," Ryuji assured him with a smile. "Besides, there are skills I'd like to learn from you, and having you close would make things much easier."

"If that's the case, I'd be grateful for your hospitality," Gyomei agreed with a nod.

When Ryuji brought Gyomei home, he found Tanjiro training in the courtyard.

"Uncle!" Tanjiro greeted him respectfully, then glanced at Gyomei curiously.

"This is Master Himejima Gyomei," Ryuji introduced.

"Good morning, Master Gyomei," Tanjiro said, bowing deeply.

"Good," Gyomei replied, his voice warm yet reserved.

At that moment, Tanjiro's younger siblings, Takeo, Shigeru, and Rokuta, approached, greeting their guest with excitement.

Gyomei, however, seemed tense, his hand subtly shifting over his rosary beads. Where he once loved children, a shift had taken place within him over time. Now, he found their innocent chatter grating.

Noticing this, Ryuji gently waved the children away to let them play elsewhere.

In a quiet room, Ryuji prepared a cup of tea for Gyomei, who sat across from him.

"Forgive me, but may I ask… has something happened in the past to change your feelings toward children?" Ryuji's tone was respectful yet curious.

Gyomei clasped his hands around the rosary, his grip tightening.

After a long pause, as if deciding whether to share, Gyomei finally let out a weary sigh. "It's... complicated," he murmured.

His pale eyes closed, and tears traced down his cheeks, hinting at the pain he carried—the once-loving guardian now haunted by the destruction demons had wrought upon his life.

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