Kim falls for the latest craze sweeping Middleton High, Animology, which purports to predict personality and romantic compatibility. Along the way, she and Ron have to stop Señor Senior, Senior's scheme to destroy the Billionaire's Club and deal with Animology's prediction that Señor Senior, Junior is her soul-mate.
While Kim and Ron were jet-skiing to the Billionaire's Club island, in the boats leaving can be seen a variety of Middleton Background Characters. Most notable were, in order, the cheerleaders Hope, Jessica, Marcella, Liz, "Eunice Brower"(fanon name), Crystal, Tara, and "Lacy"(fanon name). In addition the girls fanon call "Ashley"(purple top) and "Alex Sapphic, aka 'The Background Lesbian'"(red top) were in a boat just before Crystal's.
How could Kim not see them?
Maybe because they were all on the side which Kim's hairstyle blocks most of her peripheral sight.