Watashi no Hara no Naka no Bakemono

Chinatsu is an honor student with many friends, a timid girl who’s usually trying to get along with everyone. When she starts having her period, something else seems to change within her, she realizes her feelings, which she had been pretending not to notice, the “monster” inside her begins to rampage and reveal its true nature. She gives in to the urge to hurt her surrounding.Original Web Manga