If the manhwa adaption follows the novel, it will take several chapters to see him.
We don't see much of him, because he will be paired with Grayson in the story that will be released in korean on wednesday. Since that pair was already planned since "Kiss me if you can" came out as novel (or even before), it looks like the author was careful not to add too much of him in her other novels to avoid spoiler for the not written novel where he is part of the main pair.^^
Wow! Thank you!
They are releasing his story in korean right now: https://ridibooks.com/books/5375000983
WHERES THE FIREFIGHTER