Akumu no Merumaga ~Ochita Imouto wa Kaerenai~

“Welcome home, big brother.”
It had been several years since I’d returned home. The first person to greet me was my younger sister, Nana.
Even though I knew she was my sister, my heart was racing at how much she’d grown into a woman.
When I left, she wasn’t exactly feminine, to say the least. But now…
“What am I thinking…? She’s my sister, you know?”
It was late at night. I heard the sound of a door opening outside my room.
Footsteps soon followed, so it was probably Nana coming out.
“You’re awake?” Perfect. If she’s still awake, let’s talk for a bit.
I thought she’d gone to the bathroom or get something to drink, but… Nana was in an unexpected place. “Nana, where are you going at this hour?”
“Uh… well… I was thinking of going to the convenience store to do some shopping…”
“Does it have to be today? Couldn’t you just get up early tomorrow morning? Or is there something special happening today? If so, I’ll go with you.”
“Um… ah, well… you see… I mean, that’s not good. I mean, I’d like you to wait for me, big brother…”
I felt a sense of relief.
Only her body had changed; her personality was the same as before. She was still my slightly timid little sister.
“–Nana, promise me one thing. That you won’t do anything to worry Mom and Dad.”
“Big brother… Yes, I understand. I’ll be going now. Thank you, big brother. And I’m sorry…”
Several weeks passed.
Nana went out at night frequently.
But for now, I had no intention of scolding her. I didn’t have any intention of doing so…
Then, I received an email that signaled the beginning of that nightmare…