When the app is launched, a ghost appears. Developed by four young adults, the app becomes the centerpiece of a livestream where they venture into a supposedly haunted mountain to prove its authenticity—only to meet a grim fate.
| Actor | Role |
|---|---|
 Kim Young-jaeDong-ju | Dong-ju |
 Kim Ju-aHan-byeol | Han-byeol |
 Yang Jo-aSun-young | Sun-young |
 Kim Hee-jungNa-yeon | Na-yeon |
| PPark Seo-jiJin-seo | Jin-seo |
 Kim Young-sunSun-young | Sun-young |
 Anupam TripathiSuneta | Suneta |
 Limm Yea-eunCollector | Collector |
| SSon Min-zunMin-zun | Min-zun |
 Lee Seung-yeonEun-ah | Eun-ah |
 Kim Gyu-namHa-rin | Ha-rin |
| KKim A-cheonGrandfather | Grandfather |