There exists a malevolent group who wear peculiar robotic suits and plan to conquer the world. They go by the name "Phantom" among their members, although one of them, Tenkawa Toichi, poses as a regular high school student to avoid suspicion.
When a new student, Maishima Kokoro, arrives at the school, she catches everyone's eye with her stunning beauty. However, she shies away from any romantic or intimate relationship. In reality, she is humanity's last hope against the wicked army: Maishima transforms into "Mighty Heart," the Angel of Judgment, in times of trouble. Unfortunately, she is weak in battle and frequently takes severe beatings.
Nevertheless, Mighty Heart has a powerful weapon that activates when she becomes extremely bashful. When blushing or crying, she can unleash the "mighty beam," a potent projectile equal to the destructive force of 1 ton of TNT. This phenomenon occurs often, particularly when subjected to sexual harassment, resulting in her being the organization's last option in fights.
The series also features a collection of one-shot stories, including "Onekomimi" and "Onekomimi 2," in Volume 1 and Volume 2, respectively.
