Hmmm...My guess is maybe just Jinyoo memory was altered. Perhaps Jinyoo could have perhaps had his memory forcefully altered either for his sake or Gyuh-Wool did it. Because the picture.... Clearly something isn't adding up. Argh, so many questions...
My guess is that he is gay and he confessed to the one jerk guy who was his best friend before that. When he became an outcast, he tried to kill himself and caused some kind of brain damage or amnesia with the attempt.
Wow... That's a good guess.
I kind of enjoy this so far. So many mysteries. Why Jinyoo has memory loss? Why Gyuh-wool is like this and why he's so obsessed with Jinyoo? What's happening with Sungtae? And why does Jinyoo get horny with all this? I wonder if it has to do with his memory.