No way Otcho is "Friend", for the same reason that the police officer had doom signs written all over him: these things don't get revealed so early into the series, they're still introducing characters for Christ's sake!
@Vainfire For all we know, Urasawa might want us to get a better sense for who the villain really is. Instead of a last minute reveal, we have a greater understanding of why Friend is creating his little cult. We expect a twist, but the real twist is that there is no twist.