The kingdom's aristocracy gathers in a glittering social scene where Lady Agnes, the beautiful daughter of Count Leberge, is celebrated as the Rose Among Thorns. Bernard, the fifth son of a rural viscount, is a penniless knight who scrapes by on his own merit. Five years before the story begins, at his first ball, Bernard bravely approaches Agnes only to be met with what he believes is a look of scorn. This misunderstanding festers, and he carries a grudge against the haughty noblewoman.

When Agnes's father, the chancellor, is disgraced in a political embezzlement scandal, the family loses everything. Overnight, Agnes becomes a fallen aristocrat, abandoned by everyone who once sought her favor. In desperation she seeks out the one man who might help her: Bernard. To his surprise, she appears at his door, shabbily dressed but insisting on thanking him for a past kindness he can barely recall. Still thinking she looks down on him, Bernard offers a petty revenge: he will hire her as a lowly maid. He expects her proud nature to reject the offer, but she accepts with relief.

Agnes enters Bernard's modest household, which is staffed by the cheerful Gigi and her family: husband Dominik the gardener, eldest son Eric the handsome butler, second son Allen the cook, and twin maids Carol and Celia. They warmly welcome her despite her mysterious past. Living together, the truth emerges: Agnes has severe nearsightedness. Her so-called disdainful look was merely her squinting to see. Bernard feels a pang of guilt but also begins to see her gentle, hardworking side. He buys her glasses and helps her disguise herself with plain clothes and hairstyles, but her beauty and earnest charm soon draw everyone's affection.

Their relationship deepens as Bernard's formidable merchant mother, Océanne, arrives for a visit. To avoid a forced marriage, Bernard asks Agnes to pose as his fiancée. Océanne sees through the ruse but genuinely approves of Agnes, pushing the pretend engagement toward a real one. Meanwhile, threats emerge: a wealthy knight named Elnesto takes interest in Agnes, and a shadowy faction seems connected to her father's downfall. Bernard, his superior Captain Lazard, and the household work together to protect Agnes. The couple finally confesses their feelings, but danger culminates in Agnes being kidnapped. Bernard mounts a desperate rescue, aided by unexpected allies, and they face political conspiracies that test their bond. The story balances romantic comedy with light political intrigue, following the couple from misunderstanding to genuine partnership.