well I don't understand anything about the hacking course and the message + above only confuses me further I can't find a solution on the net no + what's this thing?
It's really not that difficult, the passwords are basically given in the phone clues, you have to read about their birth, hobbies, ocupation, etc and link it with the password hint. But here you go.
Class passwords: (I haven't seen any others aside of these two, but I also loaded my save to get the x2 bonus so i was done in two classes)
Van Gogh's phone: sunflower (clue: ??? flower)
Sola's phone: osaka (clue: password has two A's)
girls' passwords:
Blonde: teeeenkawazu (clue: password has 4 E's, 2 A's. 12 letters long)
Brown-haired: enoc (clue: password has 4 letters.) - This one is the easiest because it's the first letter on her favorite scientists
Black-haired: 2003kpop (clue: password has 4 numbers and 4 letters).
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Also, to clarify: this game is both Netori and avoidable Netorare. If you follow the guide posted in page 2 you can avoid/chase the NTR scenes. You can also not read their chats with the other guy if you don't want to see pictures.
It's Netori because those scenes are locked out as soon as you reach max relationship with the girls (blonde also breaks up with shitty bf). So they effectively become "exclusively yours".