Anna is an intelligence agent of the Adela Kingdom and a secret agent in the royal special division known as NEST.
Born into a military family, Anna joined the army to follow in the footsteps of her parents, who died in an accident. Throughout various operations, she demonstrated exceptional tactical abilities, earning recognition and eventually a place in the intelligence division. While serving as an intelligence agent, Anna accidentally discovered that her parents did not die in an accident but during a covert mission. Determined to uncover the truth, she investigated further, only to be suspended by the intelligence division. Thinking the kingdom intentionally covered up her parents' death, she became devastated.
The one who came to her in this state was none other than the newly crowned princess. The princess revealed the truth that Anna's parents had been forced into a reckless and dangerous operation by the nobility. She then shared her plan to dismantle the corrupt noble factions and invited Anna to become a secret agent for NEST. Anna was given the codename "Osprey," symbolizing her swift and lethal ability to eliminate threats lurking beneath the surface, just as an osprey swiftly hunts fish underwater.
Now serving as the princess's deadly weapon, Anna carries out missions to eliminate anything that could bring chaos to the kingdom. Never failing a mission and leaving no evidence behind, NEST remains so elusive that certain nobles in Adela Kingdom doubt their reality, questioning if such a group could be real.
Through years of military service and covert operations have made her extremely quiet, Anna flawlessly performs any role during undercover missions. During one such mission in Burywood, she disguised herself as the cheerful manager of movie star Eugene, to the point where even the lively Eugene struggled to keep up with Anna's energy and tried to avoid her.