Background:
The oldest of three children, Marisa always knew she wanted to be a physician, and when her talent for seeing at a detailed microscopic level emerged, her interest in microbes began.  Marisa -- or Mari, as she was called by sisters Kim and Darlene -- was the quintessential good student, never receiving a grade of less than A during her college and medical school days. She learned and perfected her ability to see what had transpired to those she examined while in medical school, and decided to also study forensic medicine. Following her residency, Mari went to Zaire, and helped investigate several outbreaks of the Lassa/Marburg/Ebola virus family. She split her time between Africa and the United States for over a decade, until her sister was brutally murdered in San Francisco in 1992. Marisa raced to the Bay Area as soon as she heard the news.  Her family was devestated, and what Marisa could determine from her talent made her physically ill.

She then did something she'd never thought she would ever do -- she told someone else about her powers, and what she had learned from them. That person, Silver Avenger D.J. Johnson, Kim's fiance, swore he'd never tell a living soul, and he hasn't. Other than David Armitage, he is the only other person Kim has ever told. Johnson swore revenge upon the men who'd killed Kim, and he had that revenge in time.  Marisa, for her part, was shaken to her core.

For fifteen years, she had braved death and worse in the poorest parts of Africa. She had herself become gravely ill at times, but accepted it as part of the risk of her work. But losing her younger sister finally forced her to confront several painful truths. She decided to stay in the United States, in order to remain closer to her family, as well as to aid the criminal justice system.

It did not take long for danger to find Marisa in the halls of her lab in Los Angeles, where her parents now lived. Over the course of 1993-6, she'd noticed a pattern of anomalous pathogens in the blood work of murder and drug deaths coming from poor Los Angeles neighborhoods. She obsessively began to research it, and realized with horror that these victims had an unusual, common gene -- one that when activated would mean an epidemic similar to Ebola -- but within the United States, and limited to those who had the gene insert. It didn't take her long to hypothesize, test, and reproduce her theory in the lab. She reported her results to her superiors and to the CDC.

Nothing happened. Marisa reedited the study with her newer findings, now even more damning, and resubmitted it. When she arrived at the lab the next day, she was met by one of the men who identified themselves as members of the CDC's Epidemic Intelligence Service.  They had the problem under control, and would she please stop her research?  When she protested, they became impolite, and left after issuing several threats.  Two days later, Marisa was fired for "improper and unethical conduct."

Frightened, she headed to San Francisco, where she'd grown up. Afraid for her life and those around her, she met David Armitage by (what she thought was) chance, and was quickly recruited.  Armitage Investigations would protect her, pay her a generous salary, and would allow her to continue her research.  In return, AI Inc. would have one of the best forensic doctors in the world, and a paranormal talent to boot.  She informed her family that she would be returning to Africa, cut her hair, had minor plastic surgery performed, and began a new life.  Her identity to the world is now Mary Yagamura, though within the agency she is still called Marisa.

Tactics/Powers: Marisa took martial arts for years, mainly as a form of exercise.  She continues to study at a studio near her apartment in Berkeley.  She would never initiate combat, however, and is a pacifist for the most part.

Marisa can focus her vision to the effect of 10^8 magnification, allowing her to examine samples without the aid of a microscope. When she examines corpses, she can focus and see, from a third person perspective, the events which led to the victim's death, either violent or nonviolent.

Lifestyle: Marisa lives in a large studio in Berkeley near the University, and commutes to the AI Offices and Labs in San Francisco's Finacial District via BART. She owns a Lexus which she purchased in LA, which is her only allowed extravagance.  For the most part, she lives modestly and humbly.  She rarely dates, because she is rarely in a position to meet new people. She corresponds with her family and friends through letters, the postmarks forged by AI Inc.  She is on a Christmas card relationship with the Golden Avenger -- DJ Johnson -- now, though they used to talk more often in the years immediately following Kim's death.

Appearance: Marisa is a slight Japanese woman in her late thirties, 5'2, 115 pounds, with black hair and dark eyes.  Her voice is soft, and her manner is always polite, except when she's made a major discovery, when she becomes excited. She dresses casually in jeans and t-shirts under her lab coat, a function of working in Africa for so long.

Personality: Marisa is usually very reserved, only showing strong emotion when she is frustrated or excited about her work.  When she's speaking to someone who understands the complexities of the world virues and other microbes, she becomes very friendly and chatty.  To most, however, she will appear somewhat stand-offish. She is deeply mistrustful of the CDC now, though she'd worked well with them for years.