They say the story began in 2009, on a Reddit thread that was deleted exactly seven minutes after it went live.
A Hong Kong college kid—screen-name "Kairo"—posted a scan of a single-page fax he found in the dorm machine: no header, no sender ID, just a black-and-white image of a sheet of paper with three lines typed in 12-point Courier:

  1. YOUR NAME HERE __________
  2. TODAY’S DATE __________
  3. SIGNATURE __________
  4. At the bottom, in 4-point type, a single sentence:
    "Return within seven days or forfeit the remaining days you were promised."
  5. Kairo laughed, filled in the blanks with a fake name ("John Doe"), snapped a photo, and uploaded it. Within seconds the thread was bombarded by comments:
  • "Dude, don’t sign it."
  • "That fax number traces to a disconnected landline inside Queen Mary Hospital—the abandoned wing."
  • "My cousin got the same page in 2003; he ignored it and died on day seven. Heart just… stopped."
  • Moderators locked the thread. An hour later, Kairo’s account showed [deleted].
  • Day 1 – Kairo’s roommate heard him typing at 3 a.m.; the fax machine in the corridor kept spitting out blank pages.
    Day 2 – Kairo’s reflection in the bathroom mirror was "a half-second delayed," according to a Snapchat story he posted (since scrubbed, but cached on Wayback).
    Day 3 – He started a Google Doc titled "Countdown," shared with 17 friends. The doc contained only a descending integer: 4, 4, 4… repeated 10,000 times.
    Day 4 – The dorm’s Wi-Fi SSID changed itself to "7-DAYS-LEFT-KAIRO"; campus IT had no log entry.
    Day 5 – A food-delivery rider filmed Kairo on the street staring at a blank piece of paper that fluttered despite no wind; the 9-second clip went viral on Weibo before removal.
    Day 6 – Kairo uploaded a final YouTube Shorts video: 7 seconds of black screen, white text: "I’m sorry. If you see this, don’t answer the fax." The upload timestamp was 07:07:07 UTC.
    Day 7 – Kairo was found in the study lounge, eyes open, no pulse. The coroner listed cause as "sudden arrhythmic death syndrome" (SADS). In his hand: the original fax, now blank except for a single line printed in red:
  • "Contract fulfilled. Next number auto-generated."
  • Since 2009, the same one-page fax resurfaces every few years—always in a college dorm, always on a printer that wasn’t even plugged in. Students who sign and return it within seven days wake up on day eight with no memory of the week before. Those who ignore it… become the next Reddit thread.
  • The last confirmed sighting was March 2025 at Shenzhen University. A TikTok clip (now removed) showed a page sliding out of a powered-off thermal printer. The user’s handle? @Kairo_2.
  • Post date: seven days ago.