The Greatest Demon Lord Is Reborn as a Typical Nobody, Vol. 2 (light novel)
Available for back-order
Here Comes Trouble...One of Lydia's former soldiers, Sylphy Marheaven, is starting to suspect that this "Ard" character might just be the reincarnated form of the Demon Lord. So when she discovers his whereabouts, she packs her bags and transfers into his academy, dead set on finding out his true identity. And as if Ard's hands aren't full enough, he's got the upcoming school festival to think about, which should be fun...besides Sylphy surveilling him around the clock and the threatening letter he's just received. But, of course, isn't everything a breeze when you're the greatest Demon Lord?