Outcasts exist in this world. Zhang Chulan is an outcast hidden among ordinary people. In the first 19 years of his life, he has been careful to hide the difference between himself and others. Until one day, a mysterious girl Feng Baobao found him. Since then he has been chased by zombies, kidnapped by weirdos, and caught in unprecedented troubles. Together they embark on a journey to unlock the mysteries surrounding themselves and the Zhang family.

The Outcast is originally a web comic which was officially published in paperbook format by Zhejiang People's Fine Arts Publishing House (浙江人民美术出版社) since August 1, 2016. It began serialization under the title Yi Ren (异人, Weirdo), which was later changed to the current title. The Japanese version of the series has been serialized in the web magazine Shounen Jump+ since December 22, 2017, under the title Hitori no Shita.