The Lost Incident (ロスト
Ten years before the present, six children were kidnapped by Kiyoshi Kogami. During six months of captivity, the children were imprisoned separately in rooms with nothing but VR equipment. They were forced to Duel in a virtual arena where if they did not win, they were electrocuted and starved. After the children were rescued, the incident was covered up. This was to create the Ignis—A.I. with free will. The Ignis were created based on available data from the children and observed them as they Dueled in order to learn how to problem-solve. As the children suffered, Kiyoshi's son, Roken, heard their cries and did his best to help them, including installing Yusaku's philosophy of three reasons in him to encourage him to keep on going. Eventually, Roken was unable to bear the guilt and terror, and he alerted the authorities, who rescued the six children and then returned them to their homes.
In the aftermath of the incident, several of the children suffered from post-traumatic stress disorder, with some taking years of therapy to recover, while others did not recover at all. Yusaku was unaware of Roken's identity, and he theorized that he might still be captured, unaware that Roken would come to lead the Knights of Hanoi. SOL Technologies covered up the Incident, reportedly infecting Kiyoshi with a computer virus that left him comatose and only able to exist within LINK VRAINS. In reality, Lightning, one of the Ignis, infected Kiyoshi with the virus.
The project's name is the main reason why Yusaku and Kolter suspect the Knights of Hanoi of a major involvement in the incident and thus why they pursue them. Roken confirmed his knowledge of the incident during his Duel with Yusaku. Dr. Kogami, Dr. Genome, Klarissa Turner and Alec were all present during the incident, watching the victims' suffering.
- Yu-Gi-Oh! VRAINS episode 01919: "The Lost Incident"
- Yu-Gi-Oh! VRAINS episode 02020: "A Piece of the Puzzle"
- Yu-Gi-Oh! VRAINS episode 02828: "Bugging Out"
- Yu-Gi-Oh! VRAINS episode 04343: "The Reveal"
- Yu-Gi-Oh! VRAINS episode 09696: "I Know Your Secret"
- Yu-Gi-Oh! VRAINS episode 01212: "Link the Circuit"