Nagisa's Secret

When a boy visits 3-E, Nagisa seems to be close to him, and to Karma, and the rest of the class, TOO close. But when one day Nagisa shows up with tentacles, and turns out this boy is working for Shiro. What will the class do when nagisa switches sides?

This is a Assassination classroom fanfic, I made this because NO ONE makes stories like this, that I honestly crave, so I'm making my own.
(I don't own AssClass or and of the characters except Aito ok?)