Mariko Hanzo was born to Ami and Akio Hanzo in Tōkyō-to. They were mid-level management in a small but growing Biotech firm. When she was five they were transferred to London where they spent 10 years before being transferred to the Night City office. Mariko was the middle child with an older brother and younger sister and though she found America to be something of a culture shock, she grew to like Night City.

Until the night her life went up in flames. She still doesn't know who the armoured men were who smashed into their home and murdered her parents and shot her and her siblings. She knows they were Japanese or used a Japanese Mon but she has never been able to find it again. She escaped the burning building wearing nothing but a nightgown and clutching a teddy bear and old family photo, certain everyone else in her family had died. The last thing she remembers of that night was the face of a young man over her as she passed out from blood loss and shock.

Mariko died that night and Vamp was born though it took some time for her to mature. The young man who found her was part of a street gang that took her in, sheltered her, taught her to fight, and tried to channel her almost uncontrollable anger. She became their enforcer, sometimes scaring even them with the pleasure she took in bringing tremendous violence to bare against people who crossed them.

She still does jobs for them from time to time but she's moved into other circles, always looking for that Mon and the people who destroyed her life, completely unaware that they might be doing the same thing...