Secrets of the Silent Witch, Vol. 2

Monica, the Silent Witch, has infiltrated Serendia Academy on a top-secret mission to protect the second prince. So far, she's been appointed accountant of the student council and things are going great! ...Or so she thought. With her former mentor arriving at the academy and her over-powered magic under the microscope, Monica is struggling to keep her identity hidden. As if social dances and tea parties weren't terrifying enough. And now, with a new danger closing in on the prince, will Monica reach her breaking point?

[From Yen Press]