Shimoneta could be considered a Whole-Plot Reference to Go Nagai's manga Kekko Kamen, only reversing its setting by taking place in world where sexuality is forbidden rather than maliciously enforced. In both works, the heroine is a girl who fights against the tyrannical leaders of the place by adopting a naked superhero persona in which her nudity is exploited to get away (Blue Snow and Kekko Kamen, respectively), and there's also an innocent girl who causes trouble for her attraction to one of the heroes (Anna and Mayumi) and a boy that goes under a female gender identity (Oboro and Koichi).
Right off the bat, the panties mask that soon becomes a symbol of ero-terrorism is one to Hentai Kamen, while at the same time becoming a sly dig at Anonymous and their Guy Fawkes masks.
The series's main cast is also heavily influenced by that of popular light novel Haruhi Suzumiya. SOX itself is a parody of the SOS Brigade from Haruhi Suzumiya, which the manga even lampshades in a footnote on the page where Ayame first chooses the name and explains what the acronym stands for.
Ayame shares many of the same quirks and traits as Haruhi. Aside from being both athletic girls with dark hair and eyes described as flaming, they both initially seem pushy but generally mean well, both are perverted, and they're the leaders/founders of their respective clubs. They even roped Tanukichi and Kyon into joining them as their first new members, and later develop a romantic attraction to them.
Tanukichi fills Kyon's role as the series' Supporting Protagonist, who often provides commentary on Ayame's actions. Which also makes him the designated Only Sane Man of the group, whenever he thinks she's going too far. Despite both their complaints, however, he and Kyon both eventually admit to themselves that they actually enjoy the weirdness surrounding Ayame and Haruhi, and even prefer it that way. His name also evokes Taniguchi, Kyon's perverted friend.
Hyouka is equivalent to Yuki Nagato. Both of them are emotionless, scientifically-mined girls with cold colored hair (purple in Nagato and green in Hyouka) who have a professional interest in the main protagonist (Yuki due to Kyon's influence on Haruhi and Hyouka for her interest in reproduction), rarely leave their respective school clubs (literature and science), and occasionally save the day for the brigade. Yuki even has a small arc of the Suzumiya Haruhi light novels focused on her trying to understand human love relationships.
Master looks and acts similarly enough to Alfred Pennyworth that he may be intended to be analogous to him.
Oboro's case is likely unintentional, but still looks, sounds, and acts like a gender bent version of Azumanga Daioh's Sakaki. Made moreso in the anime version thanks to Sumire Uesaka, Oboro's Japanese voice actress, sounding similar to Yuu Asakawa, Sakaki's Japanese voice actress.
Ichinose, a.k.a. White Peak, is very ostensibly a parody of Makoto Shishio from Rurouni Kenshin, in this case wearing a stiched bodysuit of white panties instead of bandages.
Oddly, given the thematical differences between the works, Annie Brown seems to be visually based on Mirai Kuriyama from Beyond the Boundary, only with bigger breasts.
Anime-exclusive
One of the "dirty" places shown to be destroyed during the opening is That Pool.
Also in the opening, you can see a heart shaped staff very similar to what Sailor Moon would use.
Again in the opening is a burning novel called ...Nights After Five. This is a shout out to the Project Ako OVAs, where one character was obsessed with an adult anime/manga series called Amy's Nights After Five.
It also shows Anna humping Table-kun nervously, albeit in a different way.
While The Silence of the Lambs was known for a Death's Head moth with a skull pattern actually composed of naked women, this show does the reverse with Anna'sWingding Eyes, which uses hearts to form the shape of a woman's body. With one heart placed down there.
Episode 10 has Blue Snow fondling a sledgehammer. Miley Cyrus would be proud.
Tanukichi pulls a fantastic submission hold on someone in the dark, represented by a black silhouette man later revealed to be Oboro. This is taken from Case Closed, any time the crime is described when the culprit hasn't been identified yet.
The beginning of Episode 2 contains an unmistakably one to Fahrenheit 451: When the moral police burns a pile of erotic magazines, there's a woman that assumes the same pose as the woman in the film when the books are burnt with a flamethrower.
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