how did you do it im sufferin
What i did was that I chose random classes but you HAVE to choose study of malediction! You won't be able to talk/find Luca unless you go to study of malediction on wednesday. After you meet luca on wednesday try to spend as much time with him as you can especially during lunch and freetime! During freetime he's usually in the library studying. On Monday and tuesday make sure to steal food from the kitchen and get your bad up to 4 to be able to skip class. You can skip any class you want but NOT study of malediction. When your skipping classes go to the kitchen to get a chance of showing luca on how to make coffee (someone said this in the comments but I wasn't able to show him how to make coffee but I was still able to get his good ending so you dont really need to do this part!). That's basically it but when your talking to him make sure to pick dialogues that you think will please him on your answer he would usually say "i agree", "your thoughts and mine are similar" etc. (somewhere along those lines lol). If he doesn't sound pleased or agree with you then go back and choose different options!
Goodluck and lmk if this helps!