kuroguro-san wa kyou mo kuroi

A manga that does not exist. On Twitter, an account called 存在しない漫画の1コマbot (Non-existent 1koma bot) posted a tweet depicting one panel of the manga. Since then various fan works have been created for this manga that does not exist. The non-existent main character for this non-existent manga is, of course, Kuroguro Uruko.