I remember stumbling onto this anime and manga I forgot the title but basically mc just got into a break up with her bf I think and she meets this girl who she befriends but then the girl she meets turns out to be a guy and keeps using the disguise to see her everywhere, I’m pretty sure it was smut too. I remember being so shocked by the entire plot though.
It was a dungeon manhwa where the mc at first dungeon spawn, meets these three fluffy gem eaters who he befriends and takes on his journey along the dungeon.
The Newbie Is Too Strong/The Overpowered Newbie
https://www.mangago.me/read-manga/the_newbie_is_too_strong/
There was this manga I once read, where the mc was a teacher of a magic school and he was teaching the lowest class, but in actuality he was an assassin. There was a new student and he was the mc’s underling or partner in his assassination- and he told the MC everyone in the class was going to become a villain when they grow up- and the MC finds ways to change their future
Hello! This BL manhua was about a new student and a guy who liked this girl in his class. The new student gets seated between them and the guy passes letters to the new student to pass to the girl he likes but the new student mistakes it as a letter to him. The guy eventually starts to like the new student.

It was basically this next in line demon lord kid who was brought to an orphanage by her nanny, and she gets adopted to go into this gifted academy to fulfill her demon duties. She finds someone to be her dad and also befriends and gets adopted with the outcast kid