Story
Fujisaki Ai, the feared police investigator with the alias "Steel Shell Ai", has the ability to metalize her limbs into formidable weapons thanks to nanotechnology enhancements.

For many years she has been hunting the enigmatic criminal organization "Sacrifice", which kidnaps women. Their female victims are often the famous: actresses, celebrities and sportswomen.

Some of these victims appeared after a long absence, with memories of what happened while they were kidnapped so fuzzy that the incidents were considered of no consequence and then forgotten. However, later on it is without exception that the name of these women are found amongst the list of prostitutes in brothels operated by criminal organizations.

What has the organization done to them to make them behave that way!?
A top-brass member of the organization, known as Awanichi, may be responsible.

An ally of Ai in challenging the criminal organization is squad leader Miyamura Yukari, and supporting Ai from the shadows is Sawamoto Miwako, a talented member of the Ministry of Interior Sawamoto Miwako, who is also Ai's mother. And finally, joining the cast is Miyamura's niece, the famous idol Kitano Mai, who was once a victim of kidnap by Sacrifice.

Committing everything they have, it has become a struggle of life and death between the evil criminals of Sacrifice and the peerless police investigator Steel Shell Ai.