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.
The fictional Japanese city named Sugomori City is built on reclaimed land. But as the years go by, the city's population is decreasing. One day, Sonosaki tells her classmate Katsuhira: "You have been selected to be a Kiznaiver." The Kizuna System, which allows Katsuhira to share his wounds, connects him to the classmates whose lives and personalities completely differ from his. The Kizuna System is an incomplete system for the implementation of world peace that connects people through wounds. All those who are connected to this system are called Kiznaivers. When one Kiznaiver is wounded, the system divides and transmits the wound among the other Kiznaivers.
In a world where humans and non-humans have not yet been separated, the kingdom of Leones is protected by the Holy Knights, powerful magic users both revered and feared by the people. Supposedly the strongest, most fearsome of these knights, the Seven Deadly Sins, betrayed the kingdom and made enemies of all the other knights. Queen Elizabeth doesn't believe this story, and sets out to find the Sins - but when she meets the first Sin at a tavern, his name is Melodias, and he's nothing but a boy in charge of the pigs.
Taken the kingdom of Leones back from Holy Knights, the Seven Deadly Sins, along with Elizabeth and Hawk, can finally enjoy peaceful lives they earned. However, with premonitions of a new threat are looming, their happy, ordinary days are about to end soon.
Kasuga Arata lived a normal life together with his childhood friend, Hijiri Kasuga, in a small town. However, everything changed on the day of the Black Sun, and a magus (mage) appeared before him. The Black Sun caused the Breakdown Phenomenon which destroyed the town where he lives. Because of this, his normal life was artificially reconstructed by a grimoire that his childhood friend had left. The appearance of the magus led him to a new life in the Royal Biblia Academy and meeting the members of the Trinity Seven.