- This article is about an in-universe event. For the in-game mission, see Lost Butterfly.
Following terrorist uprisings around the world, the United Nations Forces was planning a major assault against the terrorists by utilizing their Pacific Fleet. The UNF called on the Japan Air Self-Defense Force's 309 Squadron, and hired Arrows Air Defense and Security, to provide escort for the fleet as it made its way through the Pacific Ocean.
On the day, the fleet was scheduled to depart Tokyo Bay when unknown aircraft entered Tokyo airspace. The United Nations immediately changed the assignment to a defense operation and requested immediate assistance.