Threads of Crimson and Gold
New trope (please try it):
Micheal von Shelb, the lazy yet brilliant Duke's son, discovers he’s a disposable side character in a series of romantic dramas where the authors gleefully kill off his family and even his unborn kids. Unwilling to accept his footnote status, Micheal sets out to rewrite his destiny. Armed with his brain, wit, and slightly impractical inventions like man-bras, he vows to save his wife, Magda, restore their lives, and revolutionize the Empire.
But fate's got other plans. Between dodging political plots, equipping beastmen, and launching horseless carriages, Micheal's quiet life dream spirals into chaos. As the multiverse meddles, Micheal proves that even a side character can upstage the main plot, one sassy retort at a time.
The MC is a male, but NO HAREM, as long as he is not inventing he is thinking about how to impress his wife who is secretly stalking him.
At 1:00PM, Magda: Got to be on time to look my husband training in the garden from my foyer.
At 1:15PM, Micheal : Gotta leave on time to peek at my wife who is reading in her foyer from the dining hall.
The first volume is for the general audience, the second volume is for people who prefer to sip wine as they read.
There are three couples:
ML (genius, stalker) x FL (prodigy, stalker)
2ML (soldier) x 2FL (knight)
3ML (soldier) x 3FL (a court lady)