Responses
i don't think he forgot her, they just never really met again after he reawakened (plus he's busy with dungeons and meetings). she helped during the ant war but she retired as a hunter so she's definitely doing something else. a relationship between her and jinwoo wouldn't be good and would negatively affect the story

even though there /will/ be romance in this story, it really won't be the focus. romance comes at the end and it's just something to top the story off.
for people who preferred the healer girl simply because she was "there", she doesn't really pop up again after that d-rank dungeon. i personally think a relationship between her and jinwoo would affect the story a whole lot more.