Soul Eater (ソウルイーター) is a Japanese manga written and illustrated by Atsushi Okubo.

In Soul Eater, meister Maka Albarn and her weapon partner Soul Eater are students at the Death Weapon Meister Academy —DWMA or simply the Academy for short—located in the fictional Death City, in Nevada, United States. The school has many other students including Black Star with his weapon partner Tsubaki, and Death the Kid with his twin weapon partners Liz and Patty. The school is run by Shinigami, Death himself, as a training facility for weapons and the human wielders of those weapons, the meisters. Maka's goal, along with the other meisters, is to have their weapons defeat and absorb the souls of 99 evil humans and one witch, which will dramatically increase the power of the given weapon and turn them into Death Scythes, weapons capable of being used by shinigami. In the universe of Soul Eater, witches are powerful beings and the natural enemies of DWMA, as almost all of them have a destructive nature and desire chaos.

Shortly after the start of Soul Eater, Maka and Soul Eater face off against the forces of the witch Medusa, who forces her child, the meister Crona and Crona's weapon Ragnarok, to collect non-evil human souls to transform Crona into a kishin, an evil demon god. Medusa and her cohorts attack the DWMA on the eve of the festival commemorating its founding with the intention of reviving Asura, the first kishin who nearly plunged the entire world into madness before being sealed beneath the DWMA by Shinigami. Despite the combined efforts of Maka, Black Star, and Death the Kid, Medusa's group successfully revives Asura, who leaves to spread chaos around the world after a brief battle with Shinigami. However, Medusa is seemingly killed by the meister and DWMA teacher Franken Stein in the process, while Crona surrenders to the DWMA and goes on to enroll there and befriend Maka.

As a result of Asura's spreading madness, Medusa's older sister Arachne comes out of hiding after 800 years. Arachne reforms her organization Arachnophobia, which poses itself as a serious threat to the DWMA. The DWMA calls in the Death Scythes around the world to aide in the fight against Arachnophobia. During this time, Medusa is proven to be alive and possesses a young girl named Rachel, and Maka and the other students grow progressively stronger as they train to battle the new threat. Medusa makes a truce with the DWMA for a time so they can annihilate the threat of Arachnophobia together. The DWMA students and Medusa's entourage infiltrate the castle Baba Yaga where Maka defeats Arachne, only for Medusa to betray the DWMA and take possession of Arachne's discarded body, regaining her lost strength, as well as recruit Crona back to her cause. Meanwhile, Death the Kid is captured by Noah, an enemy posing as the former meister Eibon. Following this, the meister unit Spartoi is formed at the DWMA to take down Noah, and Maka finally succeeds in turning Soul Eater into a Death Scythe.

The anime series deviates from the manga considerably after episode thirty-five. After giving the DWMA information on Arachnophobia, Medusa takes advantage of Stein's increasing madness to lure him away with her. The DWMA manage to bring back Stein, and Maka defeats Medusa. Shinigami and Asura resume their fight, which results in Shinigami's defeat when Asura threatens Kid's life. Asura eats Arachne's soul, and is confronted by Maka, Black Star, and Kid. In the final battle, the three defeat Asura and the world returns to normal.

from Wikipedia