Quote Originally Posted by Buffalobiian
Hmm, I think you're probably right, about the fun part that is. I was sort of thinking he killed someone (don't know why, Ghost Hound influence here), but now that he says "I'll become strong, I have someone to protect" implies that he was weak before. Suicide fits weakness better than homicide I think
When watching this ep, I also watched the OP.
You have a scene with Sana on a pedestrian crossing, it's raining, grey sky, people passing by fade, he is sad looking, head down.
He has earplugs on, then camera shifts to his left hand, the mp3 player LCD text changes to "Bye"

It may be a strong indication that he tried to suicide himself.

I wonder how Nanaka will react when she learns he also has a very heavy burden and she only focused on her... never carrying for what may have happened to him. The camera focusing on his watch we think to be a key, may higlight this. That being a reaction to Nanaka saying he forgot her and was havin fun with his new friends.