Angela Johnson, often called AJ by those close to her, is a supporting character in the series who serves as the personal assistant and trusted right-hand to Sir Edward Lampard, a high-ranking Savior from the British branch of the White Knight Order. She is a young woman of twenty years with long blonde hair and green eyes, possessing a well-endowed and attractive figure. Her typical attire is a British-style maid uniform, though she has been seen in casual clothing such as a pink blouse and skirt. When engaging in missions or combat, she wears a violet battle suit. As a highly experienced Savior, Angela holds an A Rank, demonstrating considerable power and skill.

In terms of personality, Angela is defined by her deep devotion and loyalty to Edward, willing to risk her life solely for his sake. She is a stern and serious individual whose demeanor can only be tolerated by a select few, including Edward, the protagonist Moroha Haimura, and the heroine Shizuno Urushibara. Despite her fierce and sometimes ruthless nature as a fighter, she is not an obedient puppet; she is capable of defying Edward's orders if she judges his actions to be wrong. Her motivations are intrinsically tied to her service to Edward, whom she secretly loves, as evidenced by her blushing when making dinner plans with him and sleep-talking about him.

Her primary role in the story is as a formidable ally and occasional adversary to the main characters. Early on, she acts on Edward's orders to test Moroha's abilities, attacking him while hiding her identity. She harbored intense hostility toward Moroha due to his rivalry with Edward, and she was angered when he held back against her during their first fight, even though she wounded his leg. However, as the series progresses, she comes to respect Moroha's power, considering him a man second only to Edward. She works alongside him as an excellent team, though they often find themselves in embarrassing situations. Her relationship with Shizuno Urushibara is more complicated; she gets annoyed by Shizuno's familiar attitude and has been blackmailed by her with confidential information, yet she still provides Shizuno with intelligence when needed. She is also one of the few people, along with Shizuno and Moroha, who can tolerate her strict personality.

Regarding her abilities, Angela is a White Iron type Savior, which allows her to manifest weapons from her body. She is noted for her mastery of dual blades, being the first character shown dual-wielding short swords of unknown Origin. Her swordsmanship is her preferred combat method, making her a ferocious opponent who is not afraid to face any enemy. In addition to her physical combat skills, she can utilize Light Arts, which are a form of magical technique. Specific abilities she possesses include Taisai and Keikou, though the precise effects of these skills are not broadly detailed.