For example, chapter 4 is about Kotoko's friends, Miki and Satou, who also were at that goukon in chapter 1. Satou is the tall one, Miki is the one with the "Lolita" style (golden blonde hair, colored contact lenses, etc.) who was mocked by some bitch who said Miki was too old for that.
Do you mean Kanako maybe ? Satou is the "bitch" who mock Miki and Kanako is the other friend. Maybe it's a good twist that Miki go out with Satou, but it make more sense she go out with Kanako.
Oh, so it was Satou who made fun of Miki at the goukon? I was certain it was some other girl, lol, memory played me a trick.
I agree that Kanako would have been a good match for Miki... but, actually, the story in chapter 4 is indeed about Satou and Miki. Believe it or not, they are good old friends. (Yes, even though Satou said those mean things at the goukon and Miki complained loudly about the "bitch" who mocked her, the truth is that they've been good friends for a long time.)
The Spanish translation of the chapter, which I have read, includes a nice color picture of the two of them. Amusingly, the pic illustrates that very moment in chapter 1 when they were bickering in the powder room (during the goukon) and Satou accused Miki of scaring away all the boys.