@Tocnus I believe it's a couple of things. Firstly there's the fact that Yena is quite honestly amongst the weakest characters in the manga, and thus people aren't going to be cheering him on in any romance exactly.
Secondly there's the fact that the author's attempts at romance so far have been, uhm, awful to say the least. We are told Jin and Lanka like one another, but their interactions tend to undermine it. Jin kinda cares about Lanka, but it's more akin to how a zookeeper cares about animals. They are the opposite of a natural couple, and seem more forced together by the will of the author than people who would actually become an item.
With that in mind, we have an arc which establishes a relationship no one cares about involving a character no one seems to like. Yet again it feels like the author is by force establishing a couple, and yet again it kinda just doesn't work. They might be an item now, though who knows with this manga, but it's due to a Deus ex machina rather than good development.
Honestly at this point I'm not sure why the author doesn't write Yuri instead since that seems to be what they are interested in.