Only BL. 

Mostly quick transmigration (there are a lot of worlds for those who doesn't know).

Spoilers in comments of novels. 

I'm tired from novels where the MC doesn't remember his experience with ML or just don't know the ML and try to guess who is it. Oh yes, rarely the MC know the ML in person but he doesn't know that ML is this person. I can't say that it's always boring but it's a little hackneyed or trivial. Moreover, it's quite typical to the MC be dependent on the ML or the ML be hooked on the MC. 

So, the list of novels where MC and ML know each other. The MC knows ML in person, knows his hiden identity. Although there are some novels where it's not obvious for readers but it's fact and there are hints of it.