Kato Megumi: Don't Look Back, I'm Tomoya-kun

Chapter 21

"My Sister, the Ultimate Observer"

The girl originally wanted to remain stubborn, but she soon realized that if she didn't open the door, Izumi Yuu would hear her stomach rumbling.

That would be so shameful!

Thinking of this, the girl reluctantly opened the door.

"Sagiri-chan, your dinner is here," Izumi Yuu said with a gentle smile, handing the tray to the girl.

Izumi Sagiri took the tray, inhaling the fragrant aroma. She couldn't help swallowing as she carefully placed the tray on the shelf near the door. She turned her gaze back to Izumi Yuu, snorted, lowered her head in dissatisfaction, and pouted, "Hmph! Nissan clearly promised to come back early!"

"I'm sorry," Izumi Yuu immediately said, holding his hands up in surrender. He looked at her apologetically. "I got delayed because of something important. I won't do it again next time!"

"Nii-san, did you miss me?" Seeing Izumi Yuu's sincere attitude, Izumi Sagiri calmed down slightly. Her voice softened as she looked at him expectantly.

"Of course, I've been thinking about Sagiri-chan~!" Izumi Yuu replied without hesitation.

"That's good. I thought I was the only one secretly thinking about you." Izumi Sagiri turned her head slightly, muttering in a voice so soft that only she could hear.

"So, Sagiri-chan has forgiven me?" Izumi Yuu asked, a touch of joy in his voice. Little sisters were so easy to deal with! If it were a senior schoolmate, he wouldn't have gotten away this easily.

"Hmm... Wait! No!" Izumi Sagiri frowned abruptly, sniffed hard, and fixed a dark, accusing stare at Izumi Yuu. "Nii-san, you smell like another woman!"

"Huh?!" Izumi Yuu stiffened in shock.

Danger! Izumi Yuu, danger!

Sagiri sniffed again, confirming her suspicion. A gloomy expression settled over her delicate features as she clenched her fair, slender hands into fists.

"This isn't the same scent you had when you went out," she declared. "It's the scent of another woman! And you didn't cook dinner yourself, which means you ate outside. You never eat out alone, so you must've been eating with her! That's why you came home so late!"

It had to be said—when it came to catching a cheater, a woman's IQ could rival that of a death-level detective. With just a few details, Sagiri deduced Izumi Yuu's entire day's itinerary and found the exact reason for his tardiness.

Izumi Yuu stared at the girl, stunned. Is this still my shut-in sister who's afraid of communication?! With observation and deduction skills like this, she should join the Tokyo Metropolitan Police!

Suddenly, a voice echoed in his mind:

[Looking at the girl in front of you, murderous intent stirs in your heart. She deduced everything from a mere scent. Such a girl cannot be allowed to live! But before eliminating her, you think you can enjoy her first. After all, silver hair is your weakness, and she is your half-sister. What a pity it would be to kill her without savoring her, especially those perfect, exquisite bare feet. As a foot fetishist, you despise waste, so you decide to…]

"Stop right there!" Izumi Yuu shouted internally. "She's my sister! I'm not a foot fetishist, and I'm suing you for defamation!"

Shaking off the absurd narration, Izumi Yuu quickly explained, "I met a classmate today. She was going through some life issues, so I helped counsel her and then took her home. That's why I was late. Sagiri-chan is so understanding and gentle, so she'll forgive me, right?"

"Hmph!" Sagiri puffed out her cheeks, hugging a nearby pillow tightly. "You're such a lousy Nii-san! Cheating on me with another woman and leaving me home alone… And now you're making me look unreasonable, like some spoiled brat! So cunning!"

Izumi Yuu scratched his head nervously. He was about to breathe a sigh of relief when Sagiri narrowed her eyes and sniffed again.

"Wait… if you were just counseling her, why do you smell like her?" she asked suspiciously. "This level of scent transfer only happens with physical contact! At least a hug!"

"I didn't hug her!" Izumi Yuu denied flatly. As for that thing that happened… I don't even know what it was. Was it a kiss? Did she touch my lips with something else? It was so fast I couldn't tell…

Sagiri leaned closer and sniffed harder, her expression growing gloomier. "The scent is so strong. This wasn't just a casual touch. You hugged her, didn't you?!"

"There was no hug, and we didn't do anything else!" Izumi Yuu insisted. His firm tone and sincere eyes seemed to convince Sagiri for now.

Izumi Sagiri studied Izumi Yuu intently. His expression betrayed no guilt, unease, or hint of deception. Still, unwilling to let it go, she asked hesitantly, "Really?"

"Of course it's true," Izumi Yu replied seriously, his tone firm and sincere as his gaze met Sagiri's.

"But, Nii-san, you used to hate getting involved in other people's business the most," Sagiri muttered, narrowing her eyes suspiciously. Her expression suddenly shifted, as if something unpleasant had dawned on her. Hugging her pillow tightly, she continued, "Wait... you're not in love with her, are you?"

The moment those words left her mouth, Sagiri's expression grew darker and more unsettling. A strange, almost fragile energy surrounded her, as though she were on the verge of snapping.

Izumi Yu felt a cold shiver run down his spine. His instincts screamed at him that the situation had taken a dangerous turn. The girl in front of him looked as though she might break down completely at any moment—and then, with some horrifying weapon like an axe, end everything in a frenzy.

I don't want to die this way, Yu thought in panic. Not at the hands of an unhinged little sister!

"N-No!" Yu said hastily, raising his hands in defense. "She and I are just classmates who get along well."

It wasn't technically a lie. For now, he and Kato Megumi were just friends and classmates. Whether or not things would evolve beyond that was uncertain, but that was a problem for the future. At this moment, he couldn't risk saying anything to agitate Sagiri further.

Yu decided to keep it simple, avoiding over-explaining. The more he said, the worse things could get.

"Okay," Izumi Sagiri said softly, her sharp eyes studying Izumi Yu intently. After a moment of silence, she finally relaxed, her expression softening slightly. Having confirmed that Izumi Yu didn't seem to be lying, she sighed and reluctantly let go of her suspicions—for now.

Izumi Yu let out a quiet sigh of relief, grateful that he had managed to navigate the storm for now.

"Hah..." Izumi Yuu exhaled deeply, feeling the tension drain from his body. Having narrowly escaped the battlefield of Sagiri's probing gaze, he allowed himself a rare moment of relief.

"Nii-san..." Izumi Sagiri murmured softly, her eyelids drooping as her voice carried a hint of sadness and loneliness, almost as if she were on the verge of tears.

"What's wrong, Sagiri-chan?" Izumi Yuu asked, his heart aching as he saw her sad expression.

"If you're dating someone, please… don't leave me alone, okay?" Sagiri pleaded, her head drooping lower and lower.

Hearing her almost desperate words, Izumi Yuu felt as though someone had stabbed him in the heart. The accident that took their parents had left Sagiri withdrawn and fragile. Now, she had no one to rely on except him.

"Don't worry, Sagiri-chan," Izumi Yuu said gently, stroking her soft silver hair. "I'll never leave you alone."

"Really?" Sagiri lifted her head slightly, her eyes shimmering with unease.

"Of course," Izumi Yuu reassured her, smiling warmly. "I'll take care of Sagiri-chan for the rest of my life."

"People who lie have to swallow a thousand needles!" Sagiri declared, extending her pinky.

Izumi Yuu chuckled and hooked his pinky with hers, sealing their promise under the moonlight.

The accident that took her parents had left Sagiri Izumi, once a cheerful and innocent girl, withdrawn and emotionally fragile.

However, the word naive hardly suited her anymore. After all, someone drawing explicit R18 comics couldn't exactly be considered innocent. Regardless, Izumi Sagiri had no one to lean on anymore—except her brother.

And, of course, there was the guardian who had contributed significantly to her psychological scars.

"Don't worry, Sagiri-chan, I will never leave you alone," Izumi Yu said softly, his hand gently brushing through her silky silver hair. His voice carried an undeniable warmth.

"Really?" Sagiri raised her head slightly, her wide eyes glistening with unease.

"Of course, it's true." Yu smiled warmly, his tone sincere. "I'll take care of Sagiri-chan for the rest of my life."

"Okay!" Sagiri's expression brightened slightly, though she still looked hesitant. She held up her tiny, pale finger and added, "But if you're lying, you have to swallow a thousand needles!"

Yu chuckled lightly at her childlike seriousness and extended his pinky. "Understood. No needles for me because I'll never break my promise."

Under the faint glow of moonlight, their pinkies intertwined, and a silent oath was sworn.

"Now, Sagiri-chan, you can trust that I won't abandon you, right?" Yu said, his tone affectionate. Seeing how much Sagiri depended on him filled him with an odd sense of pride. Knowing someone trusted him so deeply made him feel… needed.

Sagiri nodded, her face relaxing into a rare smile. But as the realization of how much she relied on her brother dawned on her, her pale cheeks turned a soft pink. She turned away quickly, trying to hide her embarrassment.

Yu's gaze lingered on her, a small smile tugging at his lips. She looked so shy, so endearing.

[Looking at the girl who depends on you entirely, you can't help but feel your thoughts running astray. She has no one else but you. Right now, no matter how unreasonable your demands, she'd have no choice but to comply. Even if you asked her to kneel on the bed with her back to you, she couldn't refuse. The thought tempts you to—]

Born!

Pure birth!

Sagiri-chan is still a child!

The intrusive voice of the narrator echoing in Yu's mind was enough to make his skin crawl. He clenched his fists in frustration, mentally shouting, Shut up, you disgusting creep!

The audacity of the narrator to suggest such vile things about his little sister made him seethe internally. He couldn't help but reflect bitterly, If only Sagiri agreed willingly instead of being "forced"…

Wait—what?!

No, no, no! What the hell am I thinking?! Yu shook his head violently, trying to clear his mind. Sagiri is my half-sister! I shouldn't even entertain these thoughts. At least… not yet.

"Niisan, your expression just now wasn't clean!" Sagiri's disgusted voice snapped him back to reality. She was staring up at him, her delicate brows furrowed, her cheeks tinged pink.

"H-Huh?!" Yu flinched, genuinely startled.

How could she possibly know?!

[Her observation skills are astonishingly sharp. Danger! This girl must not be allowed to live any longer! But as a man of principle, you decide to give her a dignified death—with your ultimate weapon, your "invincible second brother."]

"Have you seriously gone from being a sleazy narrator to a murderer now?!" Yu muttered under his breath, completely exasperated. He ignored the narrator's increasingly absurd remarks and focused on calming his racing heart.

Sagiri squinted at him, suspicion clear in her eyes. "Don't think you can fool me, Niisan. I'm an artist, remember? An artist observes everything—every detail—and burns it into their memory. The way you looked at me just now was… weird!" Her voice faltered toward the end, and her face flushed deeper.

Yu panicked. "If you don't eat soon, your food will get cold!" he blurted, desperate to change the subject.

Sagiri pouted, her suspicion undiminished. "How obvious! That's such a clumsy attempt to dodge the topic!" she grumbled but ultimately obeyed, picking up her dinner.

Yu let out a long sigh of relief as the tension finally eased. Why does dealing with Sagiri feel more exhausting than managing that golden-haired disaster artist?

His mind wandered briefly to comparisons between Sagiri and his fellow illustrator. Both were undeniably talented, yet Sagiri's sharp wit and attention to detail made him uneasy in ways he couldn't quite articulate.

"That's right, Nii-san!" Sagiri suddenly turned and glanced at Izumi Yu, her tone unusually inquisitive.

"What's wrong?" Yu's body stiffened immediately, as if bracing for something. Being questioned by Sagiri always seemed to throw him off, and her sharp gaze made him wary.

"The person you're meeting today... it's Kashiwagi-sensei, isn't it?" Sagiri asked casually, but there was an edge to her voice.

"Y-Yeah," Yu admitted, nodding slightly. His body instinctively tensed further.

Could she be jealous? he wondered. Maybe she doesn't like the idea of someone else working as the illustrator for her light novel alongside her?

But there was another, more ironic possibility. Both Kashiwagi Eri and Sagiri—better known as Eromanga-sensei—shared the same predicament. In the eyes of those who didn't know the truth, they were both considered creepy old men hiding behind the guise of talented artists.

The thought almost made Yu laugh, but he wisely chose to keep that observation to himself.

Stone 🪨