When does Tokyo Ghoul return?

Tokyo Ghoul is a Japanese dark fantasy manga series written and illustrated by Sui Ishida. It was serialized in Shueisha's seinen manga magazine Weekly Young Jump from September 2011 to September 2014. The story is set in an alternate version of Tokyo where humans coexist with ghouls. Ken Kaneki is a college student who is transformed into a half-ghoul after an encounter with one of them.