So I’ve given a lot of thought about the anime adaptation. Instead of a straightforward review, I’ll simply talk about how I’ll adapt the story if I were the director, especially given the limitations we saw from the series. Here’s what I think, given that the series only has two seasons of 13 and 11 episodes, respectively. (I’m sorry that this got long. ;-; )
First of all, and not everyone will like this, I’ll have practically the entirety of the common route put in the one-hour long first episode. The first half of the episode will be dedicated to establishing the Occult Club, while soon jumping straight to the Rainbow River investigation (second half of Episode 6). The second half will be dedicated to the November 13 incident (Episode 7).
We just really need to know about the characters: on Kotarou’s desire to belong that led to him forming the club, and who the heroines and others are. That can be established through character interactions and Kotarou’s monologues. We can add a bit of Yoshino and Sakuya somewhere. (I’ll also do away with most of the harem jokes, but if the production committe wants fanservice… whatever.)
Two important details will be left out in the process, though: (1) the World and Yourself question, and (2) how the Occult Club even started. These can be brought up anywhere later in the series.
That will leave us with twelve episodes dedicated to the major conflict. This can go in two ways.
First, an expanded version of the anime-original route. 12 episodes will allow it to tell the story better (seriously, Episodes 12 and 13 can be expanded to five episodes – the first minute of Episode 13 especially has an entire episode worth of content). It will also allow for better-placed feecof jokes, which can be put in the early episodes. I liked the feecof jokes. I liked Anime Kagari. She was fun.
On another hand, 12 episodes also mean we can be a bit more faithful to the sauce material than that. We can have two or three heroine routes with that. As for which, Kotori and Akane routes are a must.
For a third route (Kotori route is pretty short), I’d argue that it should be Lucia Route. Sure, Shizuru Route was there to establish what Salvation is, while Chihaya Route was there to establish Sakuya. But Lucia Route gives a lot of attention to Chihaya and Shizuru, and if we want all the heroines to have major screentime in the anime despite leaving out some routes, we should have Lucia Route.
So basically, Kotori -> Lucia -> Akane, while showing (Moon) Kagari’s Theory in between these, for foreshadowing.
Though we really need Sakuya backstory, and to an extent, what Salvation would seriously look like (we need to know so we can make the most sense out of Moon Arc). One way to go about it is to add an extra scene somewhere in the final episode of (preferably) Kotori Arc, where we see Chihaya and Sakuya. Sakuya can just reminisce or dream his backstory before this. (Chihaya/Shizuru spoilers) That would be hitting two birds with one stone, while we can also add that Chihaya simply left Kazamatsuri after November 13.
That’s all for the 1st Season. The 2nd Season can go more-or-less the same as what we saw, except the first three episodes of Terra can be condensed to two episodes, while the last two expanded to three. It evens out the pacing that way. Also, if 1st Season dedicated itself to the heroine routes, (Moon) the Giant Sakuya part will have to be retconned, but Sakuya’s scene can still be played largely the same.
There are definitely better ways to go about it than what I suggested, but here are my thoughts.