The Versatile Butler Who Served a Selfish Princess Will Become a Peerless Upstart Soldier in the Neighbouring Empire summary:
After suffering for years under the impossibly selfish demands of his Lady, Princess Kurika of Athrelita, the ever-suffering butler called Litt decides that enough is enough, and flees over the border to the neighbouring Gardeldo Empire.
After taking the new name 'Lilt', he takes advantage of the Empire's meritocratic society to enroll in a prestigious vocational school to make a new life for himself, using the incredibly versatile set of skills he honed as a butler.