Soul Eater NOT! (ソウルイーターノット! Sōru Ītā Notto!) is a spin-off prequel of the main series focusing on a freshman transfer student named Tsugumi Harudori, who befriends two other Meisters named Meme Tatane and Anya Hepburn as three take part in the "NOT" meaning the Normally Overcome Target class at Death Weapon Meister Academy. She wants to learn how to control her powers in order to overcome her difficulties to have a normal life.
Shibusen, commonly known as "Death Weapon Meister Academy", is a special school for humans who're born with the ability to turn into weapons and their wielders called "Meisters". The school is split into two curriculum; E.A.T (Especially Advantaged Talet) and N.O.T (Normally Overcome Target). Those in the E.A.T use their abilities and powers to become heroes of justice while those in N.O.T just learn to control their powers with intention of not becoming a threat to not only themselves, but to others.
Tsugumi Harudori finds out she's one of the Demon Weapons, a race of human beings in which are able to magically turn into a weapon. She moves to America to attend Death Weapon Meister Academy. There, she befriends Anya Hepburn and Meme Tatane as they both become potential candidates for her meister. Throughout the series, the young thrush learns the importance of friendship and bonds as well as knowing her own strength and her self-worth as she nears the decision of choosing her meister.
According to Atsushi Ōkubo, Soul Eater NOT! takes place one year before the Prologues Arc, in which are the first three chapters and which introduce many of the main characters. A common misconception is that Soul Eater NOT! takes place a year before Soul Eater.
Keep in mind that the anime of both Soul Eater and Soul Eater NOT! do not follow the manga's official stories, change minor details, deviate from the manga, and can be inconsistent.
In the January 2014 issue of Monthly Shonen Gangan the adaptation of the prequel spin-off series was announced. The first episode premiered on April 8th 2014 and ended on July 2nd, 2014.