Mahou o Sutetai Onnanoko

When shut-in otaku Honnezaka Arumi gets thrown into an elite all-girls boarding school, life becomes hell on earth. And to make matters worse, each student at the academy gains a special kind of magic—or more like a curse, really. Arumi suddenly finds herself blurting out thoughts she never would've dreamed of saying aloud before. Luckily, there's a way to rid oneself of this magic. But unlucky for her, it involves a long and hard process.