https://www.change.org/p/pledis-entertainment-after-school-comeback
Please sign it. Pretty self explanatory.
Allkpop article:
http://www.allkpop.com/article/2016/01/nearly-3000-fans-sign-an-online-petition-asking-for-a-comeback-by-after-school-this-year
Soompi article:
www.soompi.com/2016/01/07/after-school-fans-petition-for-a-comeback/
Also if you can reblog this on tumblr here:
http://kjpopsea.tumblr.com/post/136649914325/sign-our-petition-here-to-get-after-school-to-come