For nono-Japanese followers of Sky-san, here is an English translation of Miki's background:
Miki is actually the 99th descendent of Himiko, the legendary priestess queen of Yamatai, the ancient kingdom (queendom?) of West Japan. Her power of exorcism, which runs in her bloodline all the way from Himiko herself, derives from both her superhuman muscles and her equally superhuman spiritual powers, for both of which she had been training literally from the moment she started to walk... As of present, she is 17 and is 170cm tall, weighing 211kg cold, and a staggering 278kg when fully pumped (as she usually is after an exorcism).
Warning: my VirusBuster tells me that Sky's website is currently infected with malware (or reported as such). Unless this was a malicious reporting by some prudish bible wielder (who found his muscle girl pictures to be malware), I'll stay away from the site until sky-san himself reports an all-clear