"Damsel in the Red Dress" was originally supposed to be a sort of day 1-onward story charting my FLs recovery as she goes out to find something beautiful every day for her best friend who is in the hospital, but it's become a full blown drama. It still addresses their recovery from disabling injuries, mental health issues and such, but now there is a whole lot more, complicated family histories, villainy in characters that have always been worshipped as angelic and so on. I thought the story wouldn't be able to go that far, but the more I write the more ideas I get, so it has strayed very far from my vague base concept.
For "Hushabye Prince" it's more like it evolved than that it drastically changed, but there are some details that changed quite a bit, mostly character designs. Jinwoo got a little sister who never existed in the origin plot, characters switched ethnicities, the most major change being one of my blander bully characters becoming an out-spoken and friendly drama queen (named Diva) who is much less of a bully than she was originally planned to be.