Hisako Ichiki, known as Armor, is a Japanese mutant whose story in the X-Men anime begins when she is captured by the villainous organization known as the U-Men. This event forces the X-Men to travel to Japan on a mission to rescue her.

Prior to her capture, Hisako had only manifested her powers once during her childhood. Her parents, concerned about her safety and the development of her abilities, contacted Emma Frost to help teach her how to control her emerging powers. This background establishes her as a young mutant who is still learning the extent of her abilities and who requires guidance from more experienced heroes.

During the rescue mission, a critical moment occurs when Emma Frost is placed in danger. Faced with the threat to her mentor, Hisako instinctively activates her powers to defend her, demonstrating not only her protective nature but also the trigger that allows her to finally access her abilities under stress. This event serves as a turning point, as she begins to embrace her role as a mutant hero.

Armor's primary ability is the generation of a powerful psionic exoskeleton around her body. This construct functions as an extension of her own body and can become significantly larger than her natural form. The armor grants her immense superhuman strength, allowing her to perform feats such as hurling Wolverine across a distance or assisting the X-Man Colossus in restraining a small spaceship that was attempting to take off. Furthermore, the exoskeleton provides a high degree of invulnerability, protecting her from most forms of physical harm as long as she can maintain her concentration. However, this defense has notable limitations; both laser-based attacks and Wolverine's adamantium claws have been shown to pierce her armor. She can also release her protective field as a concussive blast of energy, though this requires a great deal of focus.