(Warning: some of these may contain dark themes/images)
19 Days
Peach Love
Dawn of the Dragon (there's plenty romance, but the story is so worth it)
Dreadful Night
Boys dormitory 303
Black Mirror
Royal Servant
Coponicus No Kokyuu
One Piece dj - Pirate Ship Noah 1 (even if you're not a fan of one piece or dj, this is still a good read)
One Piece dj - Boukyaku Countdown (same for this one)
Zhen
Dark Heaven (haven't read, but have heard good things about the story)
Murderer Llewellyn's enchanting dinner invitation
The eyes of Sora
Tread lightly on thawing ice (It's honestly just an excuse to put it on this list, but you should read it)
Sleeping in my book
Rainbow city
Max Mojave Case file
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I couldn’t exactly find many bl’s with more plot than romance, but I think the eyes of sora might be just what you’re looking for. The others have a little more romance, but their plot and execution is great! I think you should check them out.
BLs with a good plot which doesn't completely revolve around romance