The Conqueror from a Dying Kingdom (Manga) Volume 4 by Fudeorca

As a student of the Knight Academy, Yuri Ho will be spending the next decade of his life in the royal capital. Eager to explore the streets of his new home, he soon finds himself in trouble when the kingdom’s first princess, Carol Flue Shaltl, follows him into the city slums and attracts the attention of a gang of kidnappers.

Unable to abandon her to her fate, Yuri will have to rely on his wits to save the princess—and himself—from harm at the hands of desperate criminals.

As they head into the deepest recesses of the city, the pair are about to discover a side of the kingdom that their privileged upbringings had shielded them from—a dark side that Carol, as the future queen, refuses to ignore.