So aren't Lukmo and Simai half-brothers and not step-brothers? If they have the same father, they must be blood-related.…
Lukmo said his father left him and his mother for a new woman, and I interpreted it as Simai being his stepson, i.e. his mother's child with a previous husband. Lukmo must have been fairly old when it happened, since he's been on his own ever since (no mention of being taken in by relatives etc). *** For them being half siblings would be a bit too much -- I doubt that would pass muster even in the BL genre. None of the "brothers" BL plotlines we've had so far has featured boys who were blood related (or at least I don't think so). It's always step brothers. As for the age difference, they do look similarly aged, but remember that Simai is an intern and Lukmo has worked at the company for years. I think there's supposed to be an age difference of at least four or five years. It's hard to tell, though, and the actors' pages don't list their age so there's nothing to go by there.
***EDIT: I was wrong about this, he did mention being taken in by his aunt.
In case it helps:Pretty good english subs, YT playlist by Lovely Things -> https://www.youtube.com/playlist?list=PLy5w5Zsc63sIuSQtLypli7odeWmPIyVufUncut…
I watched these videos and saved the playlist when I first came across your comment, but unfortunately all the videos in it (except an unrelated short film with the same actors) have since been set to private. All the other YT versions I could find have unintelligible subs.
There's a lot of romanization for her name. I just googled her, her name is also written Sakolrat, Sakonrut, Sakonrat.…
I can understand the romanisation variations of her first name, due to Thai pronunciation and different transcription conventions, but I don't think /a/ can turn into /n/ even in Thai.
First episode was just posted on Youku YouTube channel, apparently they will upload the whole series (if I understand the Google-translated text correctly). https://youtu.be/gKspbaGENOo Sadly without any English subs so far.
2 
As for the age difference, they do look similarly aged, but remember that Simai is an intern and Lukmo has worked at the company for years. I think there's supposed to be an age difference of at least four or five years. It's hard to tell, though, and the actors' pages don't list their age so there's nothing to go by there.
***EDIT: I was wrong about this, he did mention being taken in by his aunt.
Sadly without any English subs so far.
Tack så mycket för tipset!
Did you see the music video Jeff did with Gameplay?