Blue Archive Overrun by Koyuki Clones in Bizarre ‘Koyukification’ Hack

On August 31, 2025, Blue Archive players on global servers were greeted by a bizarre — and oddly amusing — surprise. The game’s troublemaking character Koyuki appeared to have taken over, with her 3D model replacing recruitment banner thumbnails and in‑game cafés suddenly swarming with multiple Koyukis.

Even the game’s information page title was cheekily changed to “nihahaha,” perfectly matching her mischievous personality. Later, the cafés were updated again to feature other students and even Hatsune Miku, but the chaos had already made its mark.

According to Nexon’s official notice (via Automaton), the breach was traced to an IP address in the Netherlands. Based on the playful nature of the incident — now dubbed the “Koyukification” by fans — it’s suspected the perpetrator might actually be a Blue Archive fan.

Importantly, Nexon’s investigation confirmed that no sensitive data, including player accounts, payment details, or core game files, was accessed or stolen. These are stored separately and undergo regular validation checks.

The company responded with additional server security measures and reported the incident to the Korea Internet & Security Agency (KISA), with whom they’re working on a broader investigation.

After roughly six hours of emergency maintenance, the game returned to normal. To make up for the downtime, Nexon is compensating all players with a generous bundle: one 10‑Recruitment Ticket, 500 AP, 150 Tactical Challenge Coins, 3,000 Expert Permits, 300,000 Credit Points, 7 Lesson Tickets, 7 Bounty Tickets, 840 Pyroxenes, and 7 Scrimmage Tickets. Players can claim these rewards by logging in until September 8 at 2:59 PM UTC.

It’s worth noting that the Japanese version of Blue Archive, managed by Yostar Games, was unaffected by the incident. 

For now, the “Koyuki apocalypse” will go down as one of the strangest — and most harmless — hacks in the game’s history.