Natsuki saves Yuri from killing herself whilst under the influence of the Perfect Yuri, by revealing that she was a transgirl, and yet despite that, she didn't care how society perceived her.
Each of the literature club girls stand up to Anthy as she tried to tear them down by exploiting their flaws.
Yuri dares Anthy to eat her but not before reminding her that she would be responsible for killing an innocent girl. This forces Anthy into throwing in the towel.
The Beach Episode
After spending a duration of the arc heckling the other girls and doing absolutely nothing to assist them with finding Sayori, Natsuki, finally having enough of her bad manners, delivers a Suplex Finisher to the Perfect Yuri.