"A family has two children, and one of them is a girl. What is the probability that the other child is also a girl?"
Hana lay on the desk, resembling a dried-up salted fish, weakly blowing bubbles.
"It's obviously one-half, so why is the answer one-third?" she murmured. "I don't get it."
"I don't understand either," added Miko, shaking her head. "It feels like it should be one-half... maybe the answer's wrong?"
Admiration for her conviction in sticking to her own logic.
When you're wrong? The answer must be wrong!
"It's a basic permutation and combination problem," Amamiya interjected, glancing at the exercise book. "The answer really is one-third."
"Wait, Natsuki-san, do you understand this?" Hana, surprised, quickly sat up straight and leaned closer to him.
"Before the children are born, the chance of having either a boy or a girl is equal, which is indeed one in two," Amemiya explained, twirling a pencil between his fingers. "But the question here specifies that one child is already a girl. We're looking at the possible combinations of the two children. We don't need to focus on their birth order."
"Stare—"
Hana's wide blue eyes fixed on him. Her eyes were as clear and bright as the sky after rain.
"...Why are you staring at me?" Amemiya asked, raising an eyebrow.
"Um..." Hana hesitated for a moment, lightly tapping her chest with two fingers, her cheeks tinged with pink. "Natsuki-san, could you say that again? I didn't quite get it."
Amemiya shot a glance at Miko.
"I understand it," Miko stated coolly.
"Then you explain it to Yurikawa-san," Amemiya replied.
"I'm sorry," Miko admitted quickly, "I didn't get it either."
Straightforward honesty is always best in learning. No wonder she consistently lands in the middle ranks during exams, with only a vague grasp on the material.
Reluctantly, Amemiya explained it again.
This time, Hana finally grasped it, and scooted even closer to him, her hands clasped together.
"Natsuki-san, can you help me with maths?" she asked earnestly.
"Uh?"
"I've always struggled with maths. I often fail my exams, which really disappoints my mom." She looked at him with pitiful eyes. "But you're good at maths. Please help me! I'll offer you a delicious reward!"
A delicious reward?
Amemiya's gaze instinctively drifted downward.
Is she really offering... that for maths help?
"Stare—"
Miko's voice cut through his thoughts, "Wipe that drool off your face, pervert."
Clearing his throat, Amemiya straightened up. "Of course, if I have time, I'll help."
"Thank you so much!" Hana beamed.
---
By 5 p.m., Amemiya sighed inwardly.
As the saying goes, bigger breasts mean less brains. Today, Amemiya had confirmed this as somewhat true.
Take Kaguya, for example—brilliant and always top of the class, but flat-chested. Chika, on the other hand, was well-endowed, but... not exactly known for her brain.
And the same seemed to apply to Hana.
Stretching with a satisfied sigh, Hana raised her arms over her head, completely unaware of the curve it highlighted. "Miko, Natsuki-san, I'm heading home."
Amemiya stood up as well. "I'll head out too."
"I'll see you off," Miko offered, following them downstairs. On the way, they encountered Miko's younger brother. Their mother was still at work and hadn't yet returned home.
After bidding farewell to Miko's younger brother, Amemiya stepped outside, leading his dog.
"See you tomorrow!" Hana waved energetically, gripping the straps of her schoolbag as she made her way toward the tram station.
The setting sun painted the sky in fiery hues, casting a warm red glow across the street and elongating the girl's silhouette. It was a beautiful sight.
If only there weren't wandering evil spirits.
...
As they walked in silence, Miko eventually broke it, her voice quiet but curious.
"Amemiya... when did you start seeing those things?"
"Last night, while I was walking the dog," Amemiya replied, not holding back as he recounted the unusual events.
There was no rule in the game about keeping it secret from others. Besides, there were dozens of players at the Ghost Academy alone, and who knew how many others in the real world? It felt fine telling Miko.
"An escape game?" Miko sounded surprised, raising her hands to cover her eyes. "I haven't encountered the game you mentioned. For me, it started a week ago... I suddenly began seeing those terrifying things. I almost lost my mind."
Being able to both see and hear the vengeful spirits, but having to pretend they didn't exist—it was a daily nightmare for Miko. She couldn't run, scream, or act in any way that might reveal her ability to see them.
But now, things have changed.
For the first time in what felt like forever, there was hope.
Grabbing Amemiya's hand, Miko's eyes sparkled with newfound determination. "So... those spirits can really be eliminated, right?"
"Of course," Amemiya assured her, explaining the effect of his spirit-dispelling aura.
"Come with me!" Miko's eyes brightened even more, and she pulled Amemiya toward her house. "Let's start by clearing out the ones hiding inside!"
"What about your dad?" Amemiya asked.
The aura's range was about five meters, but he wasn't sure what effect it might have on Miko's father. He had to be careful.
Miko hesitated for a moment before answering. "I'll watch over Dad. You can handle the spirits and contact me if anything happens."
"Got it."
Together, they returned to Miko's house. Amemiya made his way through the kitchen, living room, and bathroom, dispelling any vengeful spirits he came across. There weren't many, but each one was uglier than the last, and it was hard not to be startled when one appeared suddenly.
Once his task was complete, he said his goodbyes and headed home.
"I can finally sleep peacefully tonight!"
At 11 p.m., Miko happily set the alarm on her phone and got ready for bed. Just as she was about to lie down, she caught a glimpse of something out of the corner of her eye.
Behind the curtains, a twisted black shadow had appeared at some point...
Miko bit her lower lip in silence, her eyes welling up with tears.
"These monsters 'refresh' way too fast."
"Am I going to end up having to live with Amemiya just to stay safe?"
That night passed without a word.
---
The next morning.
After a quick breakfast of bread and a glass of milk, Amamiya left the house and headed to school.
"Good morning, Natsuki-san!" called out Chika, waving enthusiastically. Her voice was bright and cheerful.
"Morning," Amemiya responded, his eyes landing on Kaguya. He immediately noticed that she hadn't slept well.
"Kaguya-chan, your dark circles are even worse today!" Chika gasped. "Did you stay up late again?"
Kaguya bit her lip slightly, maintaining her calm and composed expression. "I didn't stay up late."
In truth, she hadn't dared to sleep at all.
How could she, when a terrifying monster stood next to her bed, watching her all night?
---
"Alright, let's get to it. Time to open the blind box," Amemiya said, breaking the tension.
The group had agreed to meet early in the classroom to open the blind boxes they got after school yesterday, just in case something unexpected happened. After all, there was no telling whether a vengeful spirit might appear.
"I'll go first," Chika announced, raising her hand as she bought the first blind box of the day and opened it.
"Hey, I got a skill card!" she exclaimed, though her excitement quickly faded. "It says that after learning it, I can change other people's names to 'Outlaw'... Ugh, what a useless skill. Bad luck!"