In Fire Emblem Fates, Demoiselle allows all male allies within a 2 tile radius of the user to receive 2 less damage during battles. It is learned by female Troubadours at level 10, and their advanced classes (Maid and Valkyrie) at any level.This skill serves as a female counterpart of Gentilhomme in this game.
Demoiselle is the French word for damsel or young lady depending on context.
Despite the femininity of this skill's name and icon, in Awakening, Brady, Laurent, Gerome, Owain, and a male Morgan can gain this skill since their mothers all have Troubadour in their class sets. The same is also true for Fates, as well.