The three little girls, Aoi, Tanjiro, Inosuke, and Zenitsu, stood in stunned silence, their mouths agape as they witnessed the incredible battle that had just unfolded before them. Kanao, usually composed, seemed lost in thought, her mind seemingly elsewhere rather than focused on the events at hand.

Mitsuri put her hands on her cheeks as they flushed. "He really won. He was so fast; for a moment, even I couldn't keep up with his movements."

Shinobu, on the other hand, stood in wide-eyed shock, her expression betraying her utter disbelief. 'How did he become so fast? No, until just a few seconds ago, I could track his movements, but then he suddenly gained immense speed in the middle of the battle. How? Could he have some kind of ability like Mitsuri or Tanjiro that gives him an advantage in battle? I can't... I can't figure it out.'

Behind Shinobu, Kenshi slowly sheathed his sword, a small smile spreading across his face.

"I wo-," he began, but was cut off by Shinobu.

"Be ready at 4 o'clock in the morning for the meeting." Saying that, she suddenly disappeared from the spot, but Kenshi clearly saw that she had dashed out towards her room.

He scratched his cheek, pondering, 'Did I make her sad? Maybe I shouldn't have been so quick...'

He considered whether he should go after her, but quickly dismissed the idea. In the Butterfly Mansion, there was one absolute rule: no one was to enter Shinobu's room without her permission, not even by accident.

"What am I even thinking?" Kenshi chided himself. "Shinobu is not a weak-willed person. I should focus on planning for the Hashira meeting tomorrow. I'll talk to her when she comes out for dinner."

As he turned around to head to his own room, a familiar face suddenly appeared before him, a scowl etched onto the person's features.

"The hell is that sword and speed?! Hahahaha, you're the perfect opponent to prove the Mountain God's strength!" Inosuke roared, leaping towards Kenshi with his blade slicing through the air.

"Inosuke!" Tanjiro and Zenitsu cried out, jumping in front of Kenshi and restraining the wild guy.

"Stop there, you idiot!" Zenitsu shouted, tying up Inosuke and dragging him back into the mansion, with Aoi and the others following behind.

Tanjiro and Mitsuri remained with Kenshi on the training grounds, the former's eyes filled with determination as he approached the swordsman.

Bowing deeply, Tanjiro exclaimed, "I am Tanjiro Kamado!"

Kenshi looked at him curiously. "Uh, I'm Kenshi Tanaka."

Tanjiro maintained his bow as he continued, "Mr. Tanaka, can you please teach me how to become as strong as a Hashira in just three days?"

Kenshi was stunned, unsure of how to respond. Seeing the lack of response, Tanjiro pressed on.

"Mr. Tanaka, my sister has been abducted by demons. I need all the strength I can get to get her back. Please, I'm willing to pay anything you ask."

Kenshi sighed heavily. "First of all, you can stop bowing, Tanjiro."

As Tanjiro lifted his head, Kenshi continued, "I've heard your story, and I believe your sister should be safe for now. However, it's impossible to become as strong as a Hashira in just a matter of hours or days. I was nearly as strong as a Hashira before I challenged Shinobu, and in the last three days, I've only pushed through my limits to achieve the final part."

Tanjiro's eyes fell in disappointment, but Kenshi quickly added. "But if you need help getting your sister back, I'll definitely do my best to assist you."

Turning to leave, Kenshi suddenly stopped and looked back over his shoulder. "Oh, Tanjiro, I forgot to ask – what breathing style did you use in your last battle?"

"I use the Water Breathing style," Tanjiro replied. "And I used the same style in my last battle. Is there something wrong with using Water Breathing, Mr. Tanaka?"

Kenshi chuckled. "No, nothing's wrong with it. I just wanted to know more about your breathing style, that's all." Facing Mitsuri, who had been standing patiently, he bowed. "Miss Mitsuri, it's all thanks to you that I became this strong in the last three days."

Mitsuri pouted, "Kenshi, I told you to call me by name and that there's no need for formalities."

"Ah, yes, of course," Kenshi said, slightly flustered. "Mitsuri, I forgot about that."

Mitsuri's cheeks flushed pink as she replied, "I need to go now, since it's almost night. After all, I need to attend tomorrow's meeting. I'll see you there."

With that, Mitsuri disappeared, leaving Kenshi alone with his thoughts. "Huh, she seemed a bit different today somehow," he mumbled to himself, before heading to his own room to prepare for the upcoming Hashira meeting.

Reaching his room, Kenshi freshened up and changed into his regular clothes, tying his long purple hair back. As he stood in front of the mirror, Shinobu face appeared in his mind. 

He walked and dropped face-first onto his bed, letting out a deep sigh.

"Ahh, I can't stop thinking about Shinobu. Is she upset? If not, there's no way she would have just gone back to her room without looking at me, right? Sigh, I just realized that I'm afraid of hurting her or upsetting her."

Just as he was debating whether to go talk to Shinobu or wait until dinner, a knock sounded at his door. Quickly getting up, Kenshi opened it to find Kanao standing outside, her hands clasped together nervously.

"Kanao," Kenshi greeted. "What brings you here?"

Kanao stood before Kenshi, her eyes filled with a mix of trepidation and determination. "I - that - " she began, but the words seemed to catch in her throat.

Kenshi reached out and placed a gentle hand on her shoulder. "You're not running away before saying what you came here to say," he said, his voice soft but firm.

Kanao took a deep breath and steeled her nerves. "Teacher Shinobu is injecting herself with wisteria poison!" she blurted out, the words tumbling forth in a rush.

Kenshi's eyes widened in shock. "What? What are you even talk-" His words were cut short as realization dawned on him. 'Fuck, fuck, fuck. How could I have forgotten?' he muttered under his breath, his mind racing.

Kenshi quickly pushed Kanao aside and dashed towards Shinobu's room, his heart pounding. 'The manga said she started injecting the poison a year ago. Even if she survived the battle with Doma, the poison will kill her eventually. I can't let that happen!'

In a flash, Kenshi found himself standing before Shinobu's door. Without hesitation, he kicked it open, the wooden frame splintering under the force of his blow.

Inside, Shinobu sat in a chair, a syringe filled with a purple liquid clutched in her hand. As Kenshi burst in, she quickly hid the syringe behind her back and rose to her feet, her expression a mix of anger and alarm.

"Kenshi, you know you're not allowed in this room. What is the meaning of this?" Shinobu demanded, her voice sharp and accusatory.

Kenshi ignored her questions, his gaze focused solely on the hidden syringe. "What are you hiding behind your back, Shinobu?"

Shinobu's eyes narrowed, and she took a step back, her back pressing against the wall. "That's none of your business. Get out of this room now, or you'll be kicked out of the Butterfly Mansion."

Kenshi's jaw tightened, and a flash of determination crossed his features. "Shinobu, you don't need to hide that syringe. I saw it, and Kanao told me about what you're doing."

With those words, Shinobu's grip on the syringe faltered, and it slipped from her hand, clattering to the floor. She looked up at Kenshi, her eyes filled with a mixture of fear and resignation.

"Kenshi, you should not interfere in this. This has to be done. I need to avenge my sister, and... and I'm not strong enough to beat that demon," She said, her voice wavering slightly as she stepped back, her back pressed against the wall.

Kenshi took a step forward, his gaze unwavering. "And you think dying is the only way to kill that demon?"

Shinobu's eyes narrowed, a flicker of anger sparking within them. "Then what do you want me to do? I already told you, I'll never be strong enough to beat that demon!"

Kenshi's expression softened, and he spoke in a gentle, yet firm tone. "Did you already forget what I said that day?"

Shinobu's brow furrowed, confusion etched on her face. "What are you talking about?"

Kenshi took another step forward, closing the distance between them. "Didn't I tell you that I would avenge your sister for you?"

Shinobu's eyes widened, and she shook her head vehemently. "You - you're stupid. I already told you, it's impossible for a single Hashira to beat that demon. And-And I don't want you to die-"

Her words were cut off as Kenshi suddenly leaned in and captured her lips with his own. Shinobu's body stiffened in surprise, her mind reeling from the unexpected contact.