Naoto's a high school dropout and brilliant amateur tinkerer. He lives in a world that has been so over-exploited that the entire surface has become one vast machine. When a box crashes into his home containing a female automaton, it's a harbinger of change that will rock the entire globe, and give Naoto his chance to be a hero.
Two brothers lose their mother to an incurable disease. With the power of "alchemy", they use taboo knowledge to resurrect her. The process fails, and as a toll for using this type of alchemy, the older brother, Edward Elric loses his left leg while the younger brother, Alphonse Elric loses his entire body. To save his brother, Edward sacrifices his right arm and is able to affix his brother's soul to a suit of armor. With the help of a family friend, Edward receives metal limbs - "automail" - to replace his lost ones. With that, Edward vows to search for the Philosopher's Stone to return the brothers to their original bodies, even if it means becoming a "State Alchemist", one who uses his/her alchemy for the military.
Set in the year 2039, Japan is the under the rule of a multinational military force called GHQ after the country went into chaos due to the "Lost Christmas" incident ten years prior to the start of the series, when a giant outbreak of an alien virus called the Apocalypse Virus spreads during Christmas, causing the United Nations to send the GHQ to contain the outbreak and restore order. The series follows Shu Ouma, an intelligent yet socially awkward teenager who finds himself caught in the war between the GHQ and "Funeral Parlor (Undertakers)", a resistance organization led by Gai Tsutsugami, which aims to liberate Japan from the GHQ, when he meets Inori Yuzuriha, the famous Internet Singer of the band Egoist and a member of the Undertakers. Due to various circumstances, Shu acquires a genetic weapon called the Void Genome, also known as "power of kings", which allows him to extract "Voids", objects with special properties that reflect the personality of their owners from underage individuals. With his new powers, Shu joins the Undertakers to protect Inori and learns secrets and mysteries he never knew.