The story is set in 2027, one year after the end of the fourth non-nuclear war. New Port City is still reeling from the war's aftermath when it suffers a bombing caused by a self-propelled mine. Then, a military member implicated in arms-dealing bribes is gunned down. During the investigation, Public Security Section's Daisuke Aramaki encounters Motoko Kusanagi, the cyborg, wizard-level hacker assigned to the military's 501st Secret Unit. Batou, a man with the "eye that does not sleep," suspects that Kusanagi is the one behind the bombing. The Niihama Prefectural Police detective Togusa is pursuing his own dual cases of the shooting death and a prostitute's murder. Motoko herself is being watched by the 501st Secret Unit's head Kurutsu and cyborg agents.

The story follows Motoko Kusanagi, a highly skilled member of the military, whom upon meeting Daisuke Aramaki, a current chief of the Public Security Section 9, in less than desirable conditions struggles to clear her name whilst forming her own independent team with the highest priority under the sponsorship and guidance of the chief Aramaki himself. Alternative Architecture is a TV anime version of the Ghost in the Shell: Arise movies.

When a ghost-infecting virus known as Fire-Starter begins spreading through the system resulting in the assassination of the Japanese Prime Minister, Major Motoko Kusanagi and her elite team of special operatives are called in to track down its source.