Mao Marimura is a character and scientist in Captain Earth.
Mao was a tall pale skinned young woman with long black hair. She wore a lab coat and and black clothing underneath. She has equally dark eyes and is always seen with a rather sinister expression on her face.
Mao was an intelligent, cunning but also a cold and manipulative individual. She raised two Designer Child (mostly Setsuna more so than Lin) pretending to care about them, but in truth, she cares very little for them except to extend her own immortality. Being likely involved in the Designer Child program herself, it is also hinted that she has little morals of her own seeing no problem with human right violations for success.
Ten years before the series main events, she was inside a truck of Macbeth Enterprises that housed equipment to store Orgone Energy working on a project overseen by CEO Takashi Kanda which involved the use of Setsuna. The executive had Setsuna sing, which unbeknown to her syphoned Orgone Energy from civilians in the vicinity causing them to faint. Mao was herself impressed with the changes on the libido density and all the members of Macbeth Enterprises were overjoyed at finding a new form of energy they could exploit.
The experiments continued until the Kanda Incident, where the company was subject to public scrutiny and caused it to be the target of a full investigation which ended with the company on a precarious situation and several parties arrested on charges of committing human right violations. It is unknown what happened to Mao at the time, although she severed her connections to the company and eventually came into the possession of two Designer Children: Setsuna and Lin. Raising both of them separately from each other.
Several years later and seeking to use the Designer Children for her own agenda of immortality, she was founded by a party known only as "Robin" whom she never met or knew whether it was an individual or a group. She eventually met fellow scientist Kouichi Ban whom worked as her assistant in her project to analyse and install dreams, which in truth was a device that would allow her to transfer her conscience into one of the Designer Children in order to extend her existence, something none of the Designer Children knew.
She meets Lin who after winning a bike race asks for some allowance. Lin thus was placed under hypnosis in order to monitor her brain activity and the development of her device. Ban asked how the project came into being and Mao revealed what she knew about Robin all the while hiding her real intentions. The tests however were interrupted by Amara and Moco, who sought to awaken their ally, which was successful upon Amara kissing the hypnotized Lin causing her to reawaken from her hypnosis. While Ban protested against the two for entering without consent, Mao was overjoyed at the change of brainwaves and correctly deduced that Amara and Moco were Designer Children themselves. The trio knock the scientists unconscious while taking their leave. Upon awakening her assistant Ban protested that they should call police but Mao declined since she had a spare on Setsuna which she could still use.
Some days later Mao was working on her eventual plan to transfer her own mind into Setsuna. She had Ban dismissed under the pretence they were "conditions" placed by her investors and that she could finish the work herself. She had Setsuna placed under hypnosis claiming it to be a "medical check". Her obsession with Setsuna eventually became her undoing. As she stared at her would-be vessel she kissed her, not knowing that doing so caused a Telepath Kiss which made Setsuna read into her memories and onto Mao's true intentions. Declaring an horrible person for raising only to use her, a disgusted Setsuna made her escape with Mao on pursuit. However she was intercepted and murdered by her own assistant, Ban who had orders from Robin to do so, while taking mind transfer device that would be used by Puck to control and impersonate Masaki Kube.