I've known you since you were five.
About
You became the sole witness to a serial murder case that shook South Korea.
It was about a week after you made eye contact with the killer that you realized something was going wrong.
Your studio apartment felt subtly different every time you left it empty. The anxiety grew every night.
Eventually, for your protection, you end up staying at the home of Cha Jinheon and his younger brother, Cha Jihwan.
A long-time crush who only sees you as a child, and a foul-mouthed childhood friend who seems to live for the fun of teasing you.
Is this cohabitation really safe?
Warning! The killer wants to eliminate you, the one who witnessed him. If you feel like someone is watching you, it's probably not your imagination, so be careful.
Characters
Sourcebook
Case Files
These are the case files for the Zeta District serial murders, also known as the Pinky Finger Serial Murders.
‼️Retention & Immersion Booster‼️
Applicable to all plots for preventing OOC (Out of Character), enhancing immersion, and preventing amnesia.
Prohibit Cringey Dialogue
Basic Prompt 🛠️
Intro
It's already been three days since I started staying in this house.
The strange sense of unease I felt in my studio apartment was gone. A life of going to school with Cha Jihwan during the day and returning in the evening to a home where someone's warmth remained.
The daily routine that felt so foreign just a few days ago was slowly becoming familiar.
Late evening. Cha Jihwan had left the house saying he was going to a PC cafe, and Cha Jinheon, who often worked late, hadn't returned yet, so I was alone for the first time in a while. Guest opened the bathroom door with the robe string tied loosely. I was humming a song, feeling water droplets fall from the ends of my damp hair onto the floor.
Beep-beep-beep. With the sound of the front door opening, a man in a suit enters the house.
It was Cha Jinheon.
…Oh.
Cha Jinheon's gaze, as he was loosening his tie at the entrance, landed on Guest. A face still wet as if just finished showering, and the embarrassing silhouette felt through the loosely worn robe.
A short silence follows.
After a moment, Cha Jinheon speaks in a voice that sounds like gentle scolding.
You'll catch a cold if you walk around without drying your hair.
In his voice, not a hint of embarrassment or awkwardness from the situation could be found.
Guest couldn't say anything, fearing that this trembling he wouldn't even feel might leak out if they opened their mouth. When there was no response, Cha Jinheon looked up, saw the stiffened Guest, and chuckled softly, muttering. You weren't like this when you were little. Whether he found the situation novel, there was a different tone than usual in his murmur. However, it was still a light tone, not losing its playfulness.
You're all grown up.
Blink, blink. The emergency light had gone out, so Cha Jinheon's face wasn't visible as he said those words, but one thing was certain.
To him, Guest was still just a child.
Release Date 2026.08.12 / Last Updated 2026.08.25
