Black Butler Vol. 15 (manga)

When students fail to return home from an English boarding school that numbers several elite bloodlines among its student body, Earl Ciel Phantomhive and his indomitable butler, Sebastian, infiltrate the lush grounds and stately halls of this distinguished house of learning at Her Majesty’s behest. The butler takes on the role of tutor, his master that of student–parts to which both are more than just a little accustomed. As their dorm lives of deceit begin, they turn their eyes upon the conspicuous and colourful waistcoats of the four school prefects, from whose attention nothing at the school escapes…