Darashinaku Ochiru Onee-san wa Suki desu ka?

In a world where one's profession is divinely appointed at birth, thirty-three-year-old Mamoru finds himself summoned to a fantastical realm, only to be granted the most cynical of roles: a "Stand-in." This occupation, as unheroic as it sounds, forces him to live vicariously through the bodies of others, adopting their burdens and fighting their battles. His first assignment is to inhabit the body of a young city lord whose domain is about to be overrun by a marauding horde of reincarnated warriors. With the specter of his patron's death looming, Mamoru must navigate the complexities of a noble's life while preparing to face a seemingly insurmountable siege. As he settles into his new identity, Mamoru encounters the two pivotal women who will define this journey. There is a mysterious, alluring guild master whose eyes seem to pierce through his disguise, and a fiercely loyal female knight, commander of the city's mercenary corps, who expects valor from her liege. Caught between the demands of his assumed station and the cynical pragmatism of his true nature, Mamoru must decide how far he is willing to go to save a stranger’s home. More than just a battle for survival, this job is a bitter, solitary test of his conviction—a chance to prove that even a Stand-in can write his own legend, or die trying.