Technology, science, and industry—this is 1969 Tokyo, and there is no better time to be alive! But a shadow looms quietly around every corner: "Invaders" have infiltrated the populace, and nobody knows who or what they are. Only the members of the top-secret agency AEGIS know of their existence. Covertly fighting the enemy is their job, but only those with the ability to open "Gates" to another world can truly defeat...