Responses
To be fair, (though I don't know if it was something they only changed recently), the tags do say Shoujo, Shounen Ai...
and generally, that means that we are only gonna get some high-level bromance if MC is male, or non-MC couple if its female, or its one of those where the guys fall in love thinking the girl is a guy (because she's disguised or something)
Yes it is the side character's.
Also it is not shown until the last 2 volumes of this story.
Now, now, I feel like.. I'm just being deceived by that tag?