She was born in 1889 into a modestly wealthy family. Her father was an inventor, and Kazuko became sort of an assistant to him. Their greatest success (technically) was the time machine that he designed, and that after his death, Kazuko built. Going forward, it worked perfectly. Backward? Not so much. Luckily, she's mostly adjusted to life in the twenty-first century, and though she will always miss her old life, she isn't in as much of a hurry to go back to it as she was.