The Wikipedia page for the Lake Saroma 100K lists winning results from 1986 to 2013, and also notes that the current men's 100K record of 6:09:14 by Nao Kazami was set there in 2018.
https://en.wikipedia.org/wiki/Lake_Saroma_Ultramarathon
I copied and pasted the 2000 results as well as a few years before and after, so you can get a sense of just how much of an aberration Abe's record was. She won the women's race by almost an hour, and was 2nd overall in a time that would have won the men's race more often than not:
2003
Temperature during the race : 10.0-13.0 degree Celsius[22]
Finishing rate : 73.5%
Men: 1 Yoshiaki Kobayashi, Japan 6:38:06
Ladies: 1 Norimi Sakurai, Japan 7:20:02
2002
Temperature during the race : 17.0-29.0 degree Celsius[23]
Finishing rate : 60.8%
Men: 1 Yasufumi Mikami, Japan 6:48:07
Ladies: 1 Makiko Hotta, Japan 7:30:23
2001
Temperature during the race : 17.5-29.8 degree Celsius[24]
Finishing rate : 47.0%
Men: 1 Yasufumi Mikami, Japan 6:38:50
Ladies: 1 Norimi Sakurai, Japan 8:00:41
2000
Temperature during the race : 10.0-29.0 degree Celsius[25]
Finishing rate : 57.5%
Men: 1 Yasufumi Mikami, Japan 6:27:13
Ladies: 1 Tomoe Abe, Japan 6:33:11 (Current World Record of Ladies' 100 km marathon)
1999
Temperature during the race : 9.3-14.5 degree Celsius
Men: 1 Yasufumi Mikami, Japan 6:22:08
Ladies: 1 Akiko Sekiya, Japan 8:03:44
1998
Temperature during the race : 9.0-11.0 degree Celsius
Men: 1 Takahiro Sunada, Japan 6:13:33 (Current World Record of Men's 100 km marathon)
Ladies: 1 Masako Koyama, Japan 8:21:26
1997
Men: 1 Yasufumi Mikami, Japan 6:24:56
Ladies: 1 Reiko Hirosawa, Japan 8:19:48
1996
Men: 1 Patrick Macke, Great Britain 6:56:13
Ladies: 1 Noriko Kawaguchi, Japan 7:11:42