WE'RE GOING TO SAVE THE WHALES! Explanation Immediately after the release of the first K Original Soundtrack, somebody noted that one of the lines of nonsensical English in Misaki Yata's theme sounded like "We're going to save the whales!"
And Fushimi said, FUCK THE WHALES! and left Homra
SAVE THE HORSES Explanation Influenced by K - Memory of Red Chapter 6, where Anna tries to rescue a horse from SCEPTER4
Referring to the show as Project Gay. Explanation The amount of bishies and the Ho Yay are rather memetic on the internet.
Reisi Syndrome! Explanation With respect to Reisi Munakata's sparkly hair-flip in the Episode 7 preview.
Reisi bitch slapping Kuroh. Get back in the kitchen!Explanation With the joke above and the fact that Kuroh is a Supreme Chef and called Shiro's "wife" by Shiro himself (also the fact he's very feminine looking, and the joke that Reisi is sexist), to many it can look like his Curb-Stomp Battle happened so Kuroh would get back in the kitchen.
Fushimi is the Rainbow King. Explanation It's become a common crack theory on /a/ that Fushimi is somehow going to acquire all the colored auras and proclaim himself the Rainbow King, since he already has both red and blue flames.
Ironically, that was in all seriousness exactly what the Big Bad was trying to become. And Fushimi still got closer than the Big Bad ever did.
Misaki is such an angel - "Misaki maji tenshi"Explanation A very popular joke among the Japanese fandom, mostly owing to Misaki's inability to speak to girls, the fact that Saruhiko called him a "virgin", as well and his general hot-headedness and less-than-clever actions - thus resulting in most Japanese SaruMisa comics ending with Saruhiko thinking of Misaki as an angel.
Kinky Battou Explanation In Episode 5, when preparing to fight Yata, Fushimi draws his sword while saying "Fushimi, emergency sword draw" which is "Fushimi, kinkyu battou" in Japanese. And then proceeds to fight Yata while making aroused noises and clearly enjoying it. This meme goes to the extent of having a Fushimi cosplayer (KANAME) say "Fushimi, kinkyu battou" in front of an audience dramatically, then proceeding to pretend to take his pants off.
Totsuka's dying face has become some kind of meme. People photoshop it onto anything and everything.
Comparing Fushimi to Homura. Explanation Both of them are black-haired, blue-eyed and wear thick-framed spectacles. And are obsessed with a certain cheerful happy-go-lucky innocent person...
Replacing some words of Homra's Chant "No Blood! No Bone! No Ash!" with some other words. Here are some examples:
No Misaki! No Fuck! No Life! Explanation Story of Fushimi's Life
When fanarts genderbend Yata he is typically depicted as the Flat-chested girl or the Big-boobed girl Explanation a.k.a. the dumb big-boobed girl who's only good feature is her boobs.