These episodes are all supplemental to the main story. Other than the first arc (first 2 episodes) almost all the others require the main story to be understood at all. Therefore, instead of a review, I will list when each episode of this supplement should be watched. -Arc 1 (episode 1 + 2): after episode 2. -Arc 2 (episode 3 + 4): after episode 5. -Arc 3 (episode 5): after episode 10. -Arc 4 (episode 6): after episode 12. -Arc 5 (episode 7): after episode 21. -Arc 6 (episode 8): after episode 32. -Arc 7 (episode 9): after episode 41. There is probably no meaning in watching these without the main story.But these episodes do well in expanding on things mentioned in the story and building characters that are not yet important to the story (season 1), but will be important later.