Day 25 Challenge: "Worst ending"
Three nominations quickly come to mind:
I adore "Love By Chance", but the ending of the second storyline was awful - which, of course, is why they made the sequel "LBC 2" (which I also adore, despite its considerable flaws).
"2gether" is cute and enjoyable, but it ends before there's any sort of satisfying intimacy - which is why they made the sequel "Still 2gether". (Or was that their plan from the start?)
Finally, "My Bromance" is heavy (especially the second half) but dramatically really good, and already in 2014 (i.e. at the age of 16 or 17), Fluke Natouch was already such a fine actor. But gosh, that ending really really really sucks. And unlike the first two, the sequel didn't make things any better: the 2020 follow-on "My Bromance 2: 5 Years Later" (starting with the "Reunion" bridge episode) was disappointing, most of all because of the truly atrocious retcon (= modified re-telling of previous events to facilitate the sequel).
Although if there were an award for "most truly atrocious retcon", I think I would also have to consider "LBC 2" (see above).
That being said, I really like all three of these, so I hate to give any of them such a raspberry. I wish I could think of a bad BL with a particularly awful ending, but I tend to put those out of my mind as quickly as possible. Anyways, the winner is .,.. *dramatic pause with drumroll* ... "My Bromance".