There is a belief within the community that an anime adaptation has to be a pure adaptation of the source material. Due to a variety of reasons, with not enough source material being the largest, a majority of anime will diverge from the manga at some point.

3. Black Butler

Black Butler

Black Butler got its first anime adaptation in 2008, and at the time only 23 manga chapters were published. After episode 6, the series has to diverge and tell an original story and change character personalities.

4. Claymore


The biggest change comes during the final 4 episodes. Most of the anime is pretty faithful, albeit with some minor tweaks for the sake of pacing.