Can't open Django shell from PyCharm using manage.py shortcut
Try PyCharm preferences.

Project:  --> Project Interpreter -->  -->
  Ensure the correct python environment

Also double check your settings under 

Build, Execution, Deployment --> Console --> Python Console
I can run Django shell directly from terminal in PyCharm, but I can't run it from manage.py shortcut (tools -> manage.py task -> shell). But I can do any other operations using this shortcut.
When I am trying to run it using second way nothing happens.
I am using Django 1.7 and PyCharm 4.0.2.