The Butterfly Mansion was quiet in the early afternoon. The sweet scent of wisteria flowers drifted from the medicinal herb garden, and only the sound of footsteps on soil echoed from the training grounds. Kamado Tanjirou was repeatedly attempting Water Breathing, Third Form. Two days since her body became female——she'd fallen countless times during yesterday's training. Today was much the same. She couldn't find her center of gravity; her body shifted with every swing of the sword. "……Not again" She muttered in her higher voice and repositioned her sword. That's when it happened. A voice came from beyond the gate. "[crying]It's all over for meeeee!! My life is finished, finisheddddd!!" It was a high voice. But——the way it cried was exactly the same as Tanjirou knew it. Kanaki Aoi appeared at the gate. The black-haired girl who managed the Butterfly Mansion's operations. She sighed as she opened the gate. "[sarcastic]Another noisy one's arrived……" A blonde girl entered the courtyard. About 165 centimeters tall, with short two-toned hair——orange only at the front, the rest black. Orange eyes glistening with tears. Sweat shining on her cheeks as she collapsed to the ground, crying loudly. Agatsuma Zenitsu——a fellow Demon Slayer Corps member who used Thunder Breathing. Like Tanjirou, her body had become female. Yet her crying voice remained as dramatic as ever, echoing across the Butterfly Mansion's courtyard. "[crying]My voice is too high, my body's too light, everything's wrong, what do I do noooow!!" Tanjirou rushed over from the training grounds. "[serious]Zenitsu!" Zenitsu slowly lifted her face. In that instant——it stopped. The tears stopped. The sobs stopped. Everything stopped. Orange eyes stared at Tanjirou's face. One second, two seconds, three seconds. "……T-Tanjirou……" "[gentle]Yeah. Zenitsu, are you okay? Um……your body?" "……You're……incredibly" "[surprised]Huh?" "……cute" The words had slipped out without her realizing it. Zenitsu's ears turned red in real time. Her face flushed. Her neck flushed. She went rigid like stone, unable to move. Tanjirou tilted her head slightly. Cute……? About herself? What was so funny about that? "[gentle]Zenitsu? Your face is really red……do you have a fever?" "N-nothing! It's nothing at all!!" She stumbled backward, shrieking. Then. Low footsteps sounded from the veranda. "[cold]Zenitsu" It was a boy's voice. But Tanjirou recognized it——Nezuko. Masculinized Nezuko descended into the courtyard. Taller now, round eyes unchanged, staring at Zenitsu with a cold glare. Low voice, but the expression was completely Nezuko. "[cold]Don't look at big brother like that" "[surprised]Like what!? What kind of look!? I was just worried!!" "It wasn't just worry" "[angry]It was just worry!!" Tanjirou stood dumbfounded. What kind of look? Had Zenitsu made such a strange face? She hadn't noticed anything. "[gentle]You two, it's been a while——let's all get along……" Aoi watched from the veranda and sighed again. --- Afternoon came. Tanjirou and Zenitsu stood side by side in the training grounds. Since their bodies changed, neither could use their breathing techniques properly——that much was the same for both. Total Concentration Breathing required drawing massive amounts of air into the lungs to explosively boost physical ability. But with changed lung capacity, different muscle distribution, and a shifted center of gravity, their old instincts were completely useless. "[serious]Anyway, we need to find forms that match this body. We can't fight demons like this" "[scared]I know……I know, but" Zenitsu glanced at Tanjirou, then quickly looked away. In the corner of the training grounds, Giyu continued practicing her forms silently. Feminized Tomioka Giyu——long black hair loosely tied back, expressionless as she continued swinging her Nichirin sword. The Water Pillar of the Butterfly Mansion and Tanjirou's teacher. Even with her changed body, the quiet stillness of her stance remained unchanged. Tanjirou took her sword stance. Water Breathing, First Form——Water Surface Slash. She stepped forward and swung. Her body lurched. She caught herself on the soil with her hands, barely avoiding a fall. Her center of gravity shifted again. Her arm swing wasn't right. Maybe slightly better than yesterday, but still completely off. Then she felt a presence. Someone approached silently and gently offered a hand. It was Giyu. "[gentle]……Can you stand" "[surprised]Ah, yes. Thank you" Tanjirou took the offered hand and stood. Giyu's hand was still large and firm, even with her changed body. (Tomioka-san is awfully close today) It was the same yesterday. Every time Tanjirou fell, Giyu was suddenly beside her. She was usually quiet and didn't move unless necessary. But Tanjirou didn't notice that Giyu's cheeks were faintly flushed. Meanwhile. "…………" At the edge of the training grounds, Zenitsu had her forehead pressed against the wall. Every time Giyu went near Tanjirou, Zenitsu's forehead moved closer to the wall. Now it was completely pressed against it. (That guy……he's definitely looking at Tanjirou like that……! With that cool face!!) Zenitsu took her sword stance to attempt Thunder Breathing forms. First Form——Thunderclap and Flash. She needed to see if she could use it with this body. Deep breath. Step forward. Her feet tangled. "[scared]Ah——" Her body fell forward. She couldn't stop. She went straight toward Tanjirou. Crash!! The two tumbled together onto the soil. Silence. "…………" Their faces were close. Very close. Less than ten centimeters between their noses. Orange eyes and green eyes met directly at point-blank range. For three seconds, both froze. "[scared]Kyaaaaaahhhhh!!" Zenitsu shrieked and launched herself upright, sprinting to the edge of the training grounds. She pressed her face against the wall, completely red, screaming at it. "[scared]I-I'm fine! Totally fine!! Nothing happened!!" "[surprised]Huh……Zenitsu, are you okay!?" "I'm fine!!!!!" Aoi frowned from the veranda. "[sarcastic]……What is that person doing" Giyu continued her forms at the edge of the training grounds, her grip on the Nichirin sword tightening slightly. She said nothing. Her expression didn't change. She just watched. --- Evening came. Everyone gathered in the Butterfly Mansion's main hall. On the thirty-mat tatami floor sat Tanjirou, Zenitsu, Nezuko, and Giyu. Masculinized Kocho Shinobu emerged from the research room. The Insect Pillar, Kocho Shinobu——manager of the Butterfly Mansion, master of poison synthesis and medical treatment, one of the Demon Slayer Corps' highest-ranking swordsmen. Even with her male body, her calm bearing and precise speech remained unchanged. She adjusted her glasses and surveyed everyone. "[serious]I have a progress report on my analysis" The main hall fell silent. "Nemuri no Kemuri——that smoke contains demon blood. Like standard Blood Demon Art, the effect persists as long as the demon's main body lives" "[serious]So to return to normal" "We have no choice but to defeat the demon that created the smoke. That's the conclusion" Silence. Tanjirou clenched her fists. As she thought. To return to normal——she had to defeat a demon. In this body. In her current state where she can barely use her forms. "[serious]However" Shinobu continued. "During the analysis, secondary data emerged. If those exposed to the smoke become——strongly emotionally connected, the effect may temporarily weaken even before defeating the demon" There was a brief pause. Something seemed to snap. It was Zenitsu. "[excited]Strong emotion means……in other words……love!? Romantic feelings, right Shinobu!!" "[serious]I'm referring to strong emotions in general. Anger, sadness, joy——all of them" "Love too, right!!" "……Love is, certainly, one form of emotion" That was enough. Zenitsu had already stopped listening. Her orange eyes sparkled, she stood up and turned toward Tanjirou. "[excited]Tanjirou!! I——!!" "[cold]I won't give big brother away" Nezuko stood before Zenitsu with a serious expression. "[angry]Give away!? You're siblings!!" "Anyone who looks at big brother that way doesn't get through" "[angry]What kind of look!! It's a normal look!!" "It wasn't normal. It was the same in the training grounds earlier" "[scared]You were watching!? The whole thing!?" By the window of the main hall, Giyu watched the three argue quietly. Her hand on the Nichirin sword's hilt tightened slightly. Tanjirou looked between the three of them and tilted her head. (Why is everyone suddenly so loud……is it the smoke?) She had no idea what emotions were being directed at her. --- At dinner. As everyone tried to sit at the long table in the dining hall, where the scent of white rice and miso soup from Aoi's cooking drifted, a quiet war began. Zenitsu and Giyu both reached for the chair to Tanjirou's right at the same time. Their eyes met. "[surprised]……Giyu-san?" "……Just sitting" "[angry]That cool face pisses me off!!" "[cold]…………" Giyu silently pulled the chair. Zenitsu protested. Nezuko sat down boldly in the chair across from Tanjirou. "[cold]The seat across from big brother is mine" "[angry]You too!!" Tanjirou looked troubled as she glanced between the three. "[gentle]Um……everyone, let's all get along" That face——Zenitsu and Giyu both looked at it simultaneously. Both went silent for a moment. Tanjirou's troubled expression shouldn't have worked with her higher voice, yet somehow it did. Zenitsu's hand stopped pulling the chair. Giyu's gaze escaped to the window outside. Both turned their faces away at the same time, noticed each other, and quietly sparked with tension again. "[gentle]Big brother, the food's getting cold" "[gentle]You're right. Let's eat" Tanjirou smiled and picked up her chopsticks. That smile——Zenitsu and Giyu both followed with their eyes simultaneously, then both looked away at the same time. Aoi carried the miso soup and glanced at everyone's behavior, then quietly returned to the kitchen. Tanjirou ate her rice and thought. Since Zenitsu arrived, things had gotten noisy. But——it wasn't bad, she thought. This liveliness felt strangely nice, ticklish somehow……she didn't understand what made her feel this way. After the meal ended, Zenitsu came closer to Tanjirou. "[gentle]Hey, Tanjirou. About that strong emotion thing earlier, I——" Flap flap flap!! A black crow dove sharply into the Butterfly Mansion's courtyard. A Kakushi crow——a messenger for the Demon Slayer Corps. Upon landing, it cried out in a loud voice. "Emergency message! In the northwest forest, a Kakushi who was pursuing the smoke's traces has gone missing!!" The main hall fell completely silent. Kakushi——the rear support unit of the Demon Slayer Corps, responsible for post-battle cleanup and transporting the wounded. One of them, sent into the forest to pursue the smoke's traces, had vanished. The lively atmosphere from moments before disappeared without a trace. Zenitsu slowly swallowed the words she'd been about to say. Tanjirou clenched her fists tightly. (The demon is still moving) The northwest forest. That's where the Nemuri no Kemuri demon is. And one of the Kakushi who pursued it has gone missing. "[serious]……We have to go help them" Giyu looked out the window. The sky was already beginning to darken. She quietly placed her hand on her Nichirin sword. Zenitsu stood beside Tanjirou. Her eyes were completely different from the red-faced version from earlier. "[serious]Got it. I'm coming too" Nezuko stared at Tanjirou. With worried eyes. But she said nothing. The evening light painted the Butterfly Mansion's veranda orange. The wisteria flowers in the medicinal herb garden swayed in the wind. Beyond that sweet scent lay the dark northwest forest. The demon's shadow was definitely moving.