For the anime fans, in the early settings of the Natsume Yuujinchou, since Kitamoto always seems to hang out with Nishimura, the animator probably thinks that they are classmates. Two best friends usually from the same class right? There are some scenes when Kitamoto shown sitting behind Natsume in class, or is that after school hangout time?
Anyway, later on, it was shown that Kitamoto actually in another class, 2-5 together with Tanuma, the new transfer kid. Only much later, we see that Kitamoto and Nishimura are NOT classmates. But it true, they've been best friends since childhood. I think the animator not to be blame for this peculiarities, even in the manga, Kitamoto's class have not been said in the first place. Or maybe, Midorikawa wanted for each of the new transfer students (Natsume & Tanuma) to have a best friend in each of their classes?
One for Taki too then :)
Sorry for replying to an old thread. I would just like to say something in case somebody else was bothered by this.
In the early anime seasons (particularly season 1), I seem to remember seeing Natsume wearing a black uniform with the badge "I" (which stands for first year). I notice those things because *ehem* I've always thought year badges are cool *ehem*. So when you say 2-5, that should mean that a school year has passed since the story in the series began. Natsume, Sasada, Kitamoto and Nishimura might really be classmates in first year, then in second year, Kitamoto and Tanuma ended up in the same class. The class roster mostly changes when the school year changes, right?
I also seem to remember that the seasons have rotated throughout the series right before I noticed Tanuma and Kitamoto going to the same class. One indicator would be the rotation of their school uniforms (as in Japan, school uniforms change in order to fit the season). Prior to noticing Kitamoto and Tanuma in the same class, I also recall a spring episode in season 2 when Natsume and Taki met Kai--and in the end of the episode, everybody had a hanami picnic by the Fujiwara's. If I remember correctly, in Japan, the new school year starts around Spring, so some time before or after this episode, a new school year must have begun.
So maybe the animators weren't exactly wrong... :)