Moena Shinguji is a young student attending an academy in a future where humanity lives in floating cities above a polluted, uninhabitable Earth. She works as a waitress at her aunt’s cafe on the academy campus. Moena has medium-length brown hair and red eyes. Through the power of a heart-shaped amulet given to her by her parents, she can transform into her superhero alter ego, Angel Blade. This amulet is central to her dual identity; at first, Moena is unaware that she is Angel Blade, and the transformation occurs without her conscious control. That changes near the end of the first episode when her pendant is damaged, leaving her fully conscious and in control while transformed.

Moena acts as a force of justice, appearing whenever the mutants of the Dark Mother organization attack women. Her primary weapon is a sword that materializes from her heart-shaped pendant. She also occasionally rides a vehicle called the Angel Motor. When her life or the lives of others are in extreme danger, she can access a powered‑up form that manifests angelic wings of energy and makes her eyes glow white. Later, it is revealed that her true power is gravity, which emerges only in times of great peril. A noted weakness is that sexual encounters can render her helpless due to her hormones.

Throughout the original series and its sequel Angel Blade Punish!, Moena grows from a student unaware of her heroic side into a more experienced fighter. She forms strong bonds with her allies, including Shaia Hishizaki, who is the alter ego of Angel Ender, and Elphie Elfman, who becomes Angel Beretta. She also shares a close friendship with police officer Ayame Fudo and a romantic connection with Seiryu Tenmyoin. Despite the challenges she faces, including temporary loss of her powers, Moena remains determined to protect others from the forces of Phantom Lady and the Dark Mother organization.