Welcome to the forum. You are not wrong, Yoo Mi is indeed an alias of actress Kim Min-gyung, it's one of the many updates that was on my to-do list. You did a good job spotting it, as even the KMDB hasn't yet realized that Yoo Mi is an alias for Kim Min-gyung and has them on separate pages

The credit on Blue Butterfly The Amazon [1984] on HKMDB had been mixed up with another Korean actress who also uses the stage name Yoo Mi, her birth name is Lee Keum-seon. So I have moved the appropriate aliases to Kim Min-gyung's and have corrected the film credit and images, I also added a higher quality pic of the Korean poster for Golden Rose [1971] since I was using it to check for her name

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Kim Min-gyung (aka Yoo Mi)
https://hkmdb.com/db/people/view.mhtml?id=5585&complete_credits=1&display_set=engYoo Mi (aka Lee Keum-seon)
https://hkmdb.com/db/people/view.mhtml?id=80843&display_set=engSince this was quite a simple update to do, I did it now rather than wait till I'm back.
Cheers