Flandre is a main character who serves as an android maid in the service of the princess known as Hime. She is also referred to as Flan or Furandre in some translations. Physically, Flandre is depicted as a small, short individual with a childlike appearance, including blonde or light brown hair and purple, often droopy eyes. A distinctive feature is a bolt situated in a bun on top of her head, which must remain properly tightened for her to function correctly. She consistently wears a maid's uniform, which includes a white apron and a red ascot or tie.

Flandre's personality is defined by her nature as a gynoid, resulting in a generally blank expression and a limited emotional range. Her most recognizable trait is her restricted vocabulary; she only speaks a single nonsensical word, rendered as Hooba in the English version and Fuga or Huga in the original Japanese. Despite her limited speech, Hime appears to understand her without difficulty. While she typically exhibits little personality, Flandre does display moments of childishness, such as when she brings dead animals to Hime believing they could become new blood servants, or when she enjoys watching and mimicking characters from a cartoon show. On rare occasions, she shows the capacity for deeper emotion, as seen in a manga scene where she begins to cry after being told she would be held responsible for a person's death. Like other royal androids, Flandre is deeply loyal and generally fearless, though her programming prioritizes her own survival, preventing her from engaging in combat that poses a certain threat of destruction.

Within the story, Flandre acts as a constant and faithful companion to Hime, assisting with both domestic chores and combat situations. Her role is that of a powerful physical enforcer and protector, often using her immense strength to help move heavy objects or battle enemies. She contributes comic relief to offset the series' violence, with her small stature and immense power creating a humorous contrast. Her key relationships center on her master, Hime, to whom she is completely devoted. She also interacts with other members of the household, including Hiro, the protagonist, and Sawawa, Hiro's sister.

Flandre shows limited development but has a notable story arc when the screw on her head comes loose, causing her to malfunction and go berserk, developing a rebellious attitude and causing chaos until the screw is tightened by another character named Flanders, returning her to normal.

Flandre possesses several notable abilities. Her primary power is superhuman strength, allowing her to lift several tons with no effort, wield objects like large tree trunks as bludgeons, and perform feats such as throwing a person through a window. She is also incredibly durable, being made of metal that can withstand chainsaws and explosions. Her eyes have special sensor functions, including infrared and other vision modes that allow her to see hidden or invisible targets, with a German-language HUD displayed in her field of view. Flandre requires electricity to function and must recharge periodically. She is also a highly competent driver, frequently tasked with transporting the main group. Her body is programmed with a self-destruct mechanism that activates upon her master's death, though this may fail if her power is depleted. Despite her invincible nature, her extreme weight makes her vulnerable to sinking in soft substances like sand and mud, from which she cannot be easily freed.