Better to suggest an alias than just renaming the tag then, since a good deal of people know her as "Komachi Tsugumi". Also, there's little point in fixing a tag for one singular image unless you go and fix them for all images containing said erronous tag.
Because that wouldn't really solve the problem of people searching for the wrong name and not getting any results because there are still the other images that aren't tagged correctly. An admin already created the alias (I think that's what danbooru calls it) so any search for komoatsu tsugumi redirects to komachi tsugumi.
Which is standard I believe, they redirect to whichever tag is bigger. Komachi had 17, komatsu (this one) had one.
(Sometimes this leads to something awful like Tohno Shiki being known as Toono Shiki for a few weeks)