Alternative Character Interpretation: While most of the characters are simply given Character Exaggeration, some of them are rewritten more based on fandom reactions to the character over the years. This is most clearly seen with Ryou (originally a gentle, kind girl who gets her heart broken by the main character and eventually finds Second Love, but here a snarky, bitter Memetic Loser with a grudge against her sister for stealing her boyfriend and being more popular) and Kanata (originally an antagonist-turned-heroine who was forced to make her sister's life unbearable but still cared for her secretly, now a walking Twincest joke obsessed with getting Haruka's attention to the point of having no other character traits).
Broken Base: There are a small minority of Key fans who feel this parody is disrespectful of their own work, particularly the way Key has twice taken their own Tear Jerkers and left them machinegunned in a ditch.
Continuity Lockout: The anime heavily relies on Mythology Gags related to Key/Visual Arts' previous works and doesn't shy away from spoilers. Heck, the entire first episode is almost entirely composed of major spoilers for the represented series. And it's generally assumed that the viewer is already familiar with the various Key franchises, as none of the characters are properly introduced to the audience at all.
Similarly, anime-only watchers of the various Key franchises may not be aware of certain jokes based on events that were not adapted in anime, such as Akio getting stabbed, or characters that were Adapted Out like Kappei.
Episode 9 mocks multiple endings the protagonists go through, but bonus points go to Tomoya mocking Nagisa's Death By Child Birth, made even harsher when you consider Ushio, his and Nagisa's daughter is watching the events of Kaginado from a planetarium.
Another notable example is episode 10, where Nayuki falls into the same state of despair she was in after her mother Akiko was sent into a coma because of a car accident, which Nayuki (unrightly) blamed herself for. In Kanon, she said she couldn't smile anymore because her mother was always by her side. In Kaginado, she instead wishes that she has no mother because of how embarrassing Akiko has become, which is also why she can't smile anymore.
And then episode 16 has every character on a field trip in buses, which turns into 4 uncomfortably hilarious minutes of dark humour with the Little Busters! cast's, Akio's and Otonashi's public transport-related trauma played for laughs.
Ensemble Dark Horse: Kaginado has turned Ryou from "the lesser Fujibayashi sister" into a being heavily traumatised by her status as the lesser Fujibayashi sister and has become a huge fan favourite because of it.
Fan Nickname: "Dark Ryou" for Ryou, whenever she reveals her dark and cynical side.
Ho Yay: Already heavily present in Little Busters!, taken up to eleven in Kaginado with Riki and Kyousuke being treated as the one canon couple of the series. The same goes for Kappei's only appearance so far in season 2. Sunohara is again seen blushing over "Hiiragi-chan."
Memetic Loser: Part of why Ryou has snapped and holds a particular grudge against her sister.
Same with her boyfriend Kappei. Also lampshaded by said boyfriend, Kappei brings up the fact he wasn't adapted into the anime, fans hate his route and speed through his route solely to get his light orb to open up After Story and that a part of the fanbase hates him for getting together with Ryou rather than her being a true romance option for Tomoya.
Surprisingly subverted for the most part by Sunohara who isn't quite as much of a Butt-Monkey as he is in his own series.
Rescued from the Scrappy Heap: While she wasn't hated, Ryou Fujibayashi from CLANNAD wasn't particularly popular either. This was lampshaded by Ryou herself in her debut episode in Kaginado. The anime turning her personality into a darker and more cynical character who is aware of her reputation actually made her more popular with Key fans.
Tear Jerker: Episode 24, the final episode, captures the essence of Key by making the viewers cry despite Kaginado being a comedy spin-off. Not only does Ushio finally speak for the first time, but the series expands on the hard earned happy ending of CLANNAD ~After Story~ by having Tomoya and Nagisa (as adults and with normal proportions) show up to pick up their daughter from the planetarium.
