What was Naruko writing in her notebook during class in Anohana episode 6?
Her notes are translated in the fansub version of the episode (click on the images to enlarge):



Here is my own translation of the notes, since the fansub translation above missed some of the characters, resulting in slight deviation of meaning:

違うっての　やってねー！！
It's not like that. I didn't do it!!
勝手なこと　ぬかすな！！！
Don't just say whatever you want!!!
（？）遠に黙れ！！
Shut the hell up!! [Note 1]
死ね！！
Die!!
助けて
Help me

[Note 1] A word or two are missing at the beginning, probably 永遠 (forever, eternity). The translation here is my own preference.