kayano kaede
The female protagonist of Ansatsu Kyoushitsu, a cheerful girl in Class 3-E, seems to be close with Shiota Nagisa. She has green hair styled in a way that resembles cat ears and blunt bangs.
She is actually named Yukimura Akari, the younger sister of Yukimura Aguri. She used to be a child actress with the stage name Mase Haruna (磨瀬 榛名). Believing that Koro-sensei killed her sister Aguri, she transferred to Class 3-E under the name Kayano Kaede using her acting skills, trying to look for the chance of killing Koro-sensei.
It's implied that she and Shiota Nagisa are together at the end of the manga.