Cooking, laundry, cleaning, and on top of that, combat and espionage... Connie Ville, an all-powerful maid attached to Halubion Castle who can do absolutely anything, is a plain girl who desires a modest and steady life, despite possessing cheat-like special abilities. However, one day she is informed that Leinhardt, a super-handsome knight famous for being a womanizer, has become her stepbrother!? Involving her flirtatious stepbrother, her capable and manly boss, and even the beautiful second prince, this is the story of the "withered girl" Connie's work, combat, espionage, and romance(?).