In this alternate "future 1990s", Japan never went through the bubble-burst of our world, but rather, became the nexus of world finance, surpassing the United States. This is brought them the unwanted attention of terrorist groups such as the Red May, who want to take down the Japanese economy in order to destabilize the world for their own purposes. In response, the Japanese government has authorized the Special Security Force: an elite unit working outside existing legal framework, with a license to kill. For newcomer Haruka Mikawa, codenamed "Angel", the Red May insurrection is the chance for her to prove her skills to her partner Raiden ... but they soon find out that they aren't the only ones hunting terrorists, and it isn't long before the hunters become the hunted.