Why do anime intros change so much?

I’ve been watching Fairy Tail late. Great show, I love it. It is VERY funny. One thing I’ve noticed, and it is true for other anime, is the intro music and visuals change quite often. It doesn’t seem to be tied to seasons, unless the season structure is different in Japan than the NA release. I get of course that it changes because they changed it, lets not get too literal here. Is this commonplace with other Japanese shows? What’s the cultural thinking towards that (assuming that’s the root cause)?

Several things play into it.

  1. They actually sell CDs of the music regularly. Multiple OPs and EDs mean multiple singles, and either multiple OSTs, or OSTs that aren’t 90% score can be sold.

  2. It usually happens at significant points - either in the plot, or (more often) in the episode counts. (Of course, these aren’t mutually exclusive - it’s not uncommon for plots to progress at the point where a plot-related OP change would be appropriate at about the quarter/half points.) Sometimes the OP changes as the plot takes a new direction, sometimes it happens at episode 6/13/26/39 (depending on the length of the series)…which isn’t strictly multiple seasons, but it’s a sort of virtual season.

  3. Audiences expect it on longer series, and certainly aren’t going to complain on shorter ones.

  4. The creators want to, and since it’s a common way of doing things, they don’t really have to worry about confusing the audience.

This isn’t exclusive to anime, either…it’s common in toku, as well, although the EDs change more often than the OPS, there, IME. I’m not really a fan of dorama, but I’m pretty sure it also happens there, too.

Thanks for the reply! Very insightful!