User blog comment:Wahidkarzai/Series or Season?/@comment-179280-20131004181525

"Isayama-sama"? Dude, that's a bit too extreme.

Anyways, I've said it a thousand times already. It is the end of the anime. Programs in Japan aren't planned in "seasons" like they are here in occident. They planned 25 episodes and that is. The anime hasn't been anything but a big commercial for the manga, and that's how marketing works there, even if it leaves anime fans in denial.

That said, it's NOT impossible for them to make a continuation for the anime at some point in the future. Given the popularity of the series, this is quite likely, but that will only be possible once the manga has enough material. And even in that case, that will not be a second season, but a continuation, because it wasn't something planned at the start.

To summarize, no, Episode 25 is not the end of season one. It's the end of the anime.