The new series following "Gray Fruit", "Grey Labyrinth" and "Grey Paradise".
In a special skills training school, they gave young girls nowhere to go with guns and bullets, and they continued to carry out dangerous activities.
The special skill training school "Mihama Gakuen" newly established by the "National Organization CIRS"...
The girls who lost their homes for various reasons were given guns and live ammunition.
Rena who uses a pistol, Tonghua who is good at sniping, Chrissy who is good at bombing and information processing, and Saki Ninja who is in charge of spying.
As SORD members, they deal with incidents that cannot be resolved by the police and the Self-Defense Forces, and continue to carry out dangerous activities.
K County U Port——. Important people who were preparing to enter the country suddenly disappeared.
SORD members started investigating the disappearance, but whenever they were about to capture the disappearing "baggage", they would be able to escape when it was still a little bit.
Fight side by side with twin sisters of SORD member of sister school "Kyofune Sakuragaoka", and dispute.
And-the rumors of the mysterious female rider "Soul Speed" Maki who rushed through the night town.
Tracking eventually turned into a heroic death battle, tearing the body and mind together.
... But at the same time, it was a journey to the past before Rena and the others met.