I have some interesting ideas about the Friend's appearance in this chapter. Don't click the spoiler unless you've pretty much read the entire manga.
I MEAN IT! If you look at this post before reading the whole manga then you will get spoiled on two of the biggest twists in the entire story!!!!!!! DON'T CLICK!
Isn't it weird how this is one of the few times the Friend appears in public without a mask? I was thinking that maybe Urasawa made this chapter before he decided on the Friend's identity being a long-term secret, but also knowing Urasawa it's hard to believe he didn't already have that planned out from the start.
I was thinking that maybe the Friend we see in this chapter is Katsumata instead of Fukubei. I have two reasons for thinking this: One, the hair is not Fukubei's hairstyle. Two, given how much Fukubei bullied Sadakiyo and the others in his childhood group (including Katsumata) it seems believable that Fukubei would have Katsumata running around doing these Friend cult meetings in his place. Given that the Friend wears a mask all of the time later on, and that his face is a well-kept secret, nobody would know that he had someone else pose as him at these early cult meetings.
I also wonder if Katsumata already had the plastic surgery at this time. The face doesn't quite look like Fukubei's, but it's covered in shadow so of course it's hard to make out what it looks like. It'd be really interesting if Friend in this first chapter was Katsumata with his original face, unmasked.