I personally have fallen for this clever tactic myself and started to wonder who this "Friend" was before I even watched the chapters 1&2. After catching the chapters 1&2 on TV that were aired not too long before the chapter 3 came out, I just had to watch this film to find out who "Friend" was.
I am not going to disclose who "Friend" was here but I must say it was a bit of dissapointment.. it was almost impossible to guess who "Friend" was with the info provided in the movie because this character hardly gets mentioned throughout the series. I personally felt a bit cheated by this.
Other than that, however, the film in itself was entertaining and did a pretty decent job re-creating the world of Naoki Urasawa, which many said to be impossible to make into a non-anime film because of its unique and out of worldly storyline that spans close to 50 years. The scene of the music festival where Kenji performs was quite impressive. If you are planning on watching this film, my advise would be to not get too caught up on trying and guess who "Friend" is because chances are, you won't get it right.
