Belfast is a light cruiser belonging to the Royal Navy and holds the distinguished position of head maid within the fleet. She is recognized by her tall stature, fair complexion, and long white hair, often styled with a French braid, paired with purple-colored eyes. Her attire consists of a blue sleeveless maid dress with a matching headdress, a white crop top, a corset, an apron, and metal gauntlets over white arm gloves.

Her personality is defined by the competence and grace expected of her role, as she is considered highly skilled in nearly every area of her duties. She carries herself with a professional and capable demeanor, befitting her status, and has a habit of referring to herself in the third person. In the setting of Azur Lane: Slow Ahead!, which focuses on the peaceful everyday lives of the ship girls, Belfast's primary role involves her duties as a maid. A specific example of her responsibilities shown in this series is her training of a smaller version of herself to become a proper maid, indicating her dedication to mentorship and maintaining high standards for her profession.

Regarding her abilities, Belfast is noted for her above-average performance in most areas, possessing effective offensive and defensive skills that make her a versatile and powerful asset. This proficiency extends beyond combat, as her reputation as an exceptional head maid is well-earned and recognized even by older, more experienced maids. The story provides no specific information about her motivations, key relationships, character development, or her background beyond her role and affiliation.