Mendo, an operative from MID, the Antarctic Union's intelligence agency, was the sole survivor of an ambush on his tactical team during a mission, which left him with amnesia. After being rescued by a mysterious girl with silver hair who called herself “Jefuty”, they find themselves being pursued by both factions, and the two of them must work together to overcome obstacles and escape peril. As he gets closer to the truth, the veil of mystery over Jefuty's true identity is lifted bit by bit, and it becomes clear that Mendo has gotten himself embroiled in a massive conspiracy...