Mizuki was one of the fittest people I ever met. I did a conditioner with her up to Muir last April and couldn't keep up with her - despite the fact that her pack was 20 lbs heavier than mine (55lbs) and I outweighed her by 40 or 50 lbs. When she was geared up and in the mountains, she was in her element. She looked like she belonged there. And as others have said, she was very mild mannered, quiet, and very respectful. I remember going up my first friction pitch with her looming over the top. I struggled the whole way up and she remarked "good job" - a real confidence builder.
RIP, Mizuki