わがまま王女に仕えた万能執事、隣の帝国で最強の軍人に成り上がり無双する•Wagamama Oujo ni Tsukaeta Bannou Shitsuji, Tonari no Teikoku de Saikyou no Gunjin ni Nariagari Musou suru

Fed Up With Being the Spoiled Queen's Genius Butler, I Ran Away and Built the World's Strongest Army

Leet isn't just any butler. His mistress, Princess Kilik, demands the impossible—and he delivers it, seven times before breakfast. But one day, Leet decides enough is enough, and he flees for a neighboring land where the talented rise up through the ranks instead of languishing in thankless, dead-end jobs. Under a new name, Lilt, he enrolls in a training and job placement program, and rapidly discovers that, easy as "wax on, wax off," his butlering skills make him a valuable asset! (Source: MU)