TV-Series
Description
Dr. Mummy is the alias used by Mami Hiyama, a significant antagonist in Danbōru Senki W. The true identity behind the mask is revealed to be the missing younger sister of Lex, also known as Ren Hiyama. Her background is rooted in profound loss, as both her brother Ren and her father Takeshi Hiyama are deceased. This family tragedy is the central driving force behind her actions and her descent into extremism.

In terms of personality, Dr. Mummy, or Mami, is characterized by intense aggression and a remarkable intellect. She is highly manipulative and a master of deception, capable of fooling even her own allies, such as Gardyne and Bishop, by convincingly posing as her deceased brother. Her primary motivation is a singular and obsessive quest for revenge. Mami believes she is carrying out her brother's will, which she interprets as a mission to destroy or take over the Earth. This goal consumes her entirely, and she is willing to do anything to achieve it, showcasing a ruthless and unwavering determination.

In the story, Mami plays the role of a terrorist affiliated with Omega Dain before later aligning with Paradise. Her role as Dr. Mummy is central to the antagonists' schemes, and her actions drive much of the conflict in the Paradise and Omega Dain chapter. A key relationship in her life is with her brother Lex, whose memory she idolizes to a dangerous degree. Another crucial relationship is with Hanasaki Ran, who does not act as an enemy but as a savior. At the climax of the Paradise Arc, when Mami is defeated and her worldview shatters, she attempts to take her own life, unable to accept that her perception of her brother was flawed. In both the anime and game versions, Ran intervenes and prevents the suicide, either by kicking away a bomb or a gun.

This moment marks the peak of her character development. The defeat forces Mami to confront the reality that her ideology was built on a false premise, leading to a profound mental breakdown. She is portrayed as being mentally unstable, with her entire identity and purpose tied to a misguided mission of vengeance. Her development arc is a tragic journey from a grieving sister to a ruthless avenger, and finally to a broken individual forced to recognize her own mistakes.

Regarding notable abilities, Mami demonstrates genius-level intellect. She is credited with creating the Killer Droid, a testament to her technical and scientific skill. As a combatant, her ability as an LBX player is also formidable, and she comes into possession of the powerful LBX unit, Zeus, which she takes from Gardyne. Her most dangerous traits, however, are her intelligence, her capacity for deception, and her willingness to go to any length, including self-destruction, to achieve her goals.
Cast