Haruka Nogizaka's Secret: Purezza (TV)

In the OP, Alice-chan is shown sitting, holding "Excaliborg" from Bokusatsu Tenshi Dokuro-chan; later, on the train, you see just a bit of it again as she is called off the drunk businessman.

When Nogizaka's maids show up on the train, around 7:44, Nanami refers to them as "Nogizaka Maid Tai", a direct reference to the "Hanaukyou Maid Tai" anime. Alice-chan mirrors Cynthia-chan from HMT, down to her lack of speech, her shyness and, apparently, her split personality.

At about 5:00 min into the third episode, Touka accuses Yuto of calling her a pint-sized Tiger. The reference to "Toradora" is driven home when she is seen holding the palmtop tiger from from the show on her hand.

The third episode is a parody of "Hayate the Combat Butler", emphasized by the fact that Rie Kugimiya, the VA for Tōka, also provided the voice for Nagi in Hayate.

At episode 3 around 8:07, when Touka mentions "Tenjou no Gouka de mushiaki ni shiteru kara", the Tenjou no Gouka is most likely a reference to Alastor, Shana's guze partner from Shakugan no Shana. Shana was voiced by the same seiyuu as Touka, Kugimiya Rie

In the preview for Episode 3, the silhouettes are Shana from Shakugan no Shana and Taiga from Toradora. They're both tsunderes and are also played by Rie Kugumiya.

During the sound alarm in Episode 3, two girls attacked and they use their cards as a weapon. These cards similar to the animated series Cat's Eye. After the attack on their bodyguards, Tōka's butler, Mudō Koinugawa holding his light saber to protect Yūto Ayase and Tōka Tennōji. This item similar to George Lucas Star Wars franchise

In episode 3, Tennouji Touka's panchira shots are most likely also a reference to Shakugan no Shana, who also has had her fair share of panchiras

In Episode 3, Ayase Yuto told Tennouji Touka that he thought she was a middle schooler. Tennouji Touka misheard and was adamant that Ayase Yuto called her a "Tenori Tiger". "Tenori Tiger" is the famous nickname of "Aisaka Taiga" from the anime "Toradora". Tennouji Touka is also voiced by the same voice actress of "Aisaka Taiga": Kugimiya Rie.

In episode 6, Nobunaga is praying that there will be sequels of MariMite and Index. "MariMite" means Maria Sama ga Miteru and "Index" means To Aru Majutsu no Index anime series. Also the note says that "Redei Bato will get animated". This note reference of the upcoming anime series of Tsukasa Kozuki's Ladies versus Butlers.

In Episode 6, there is a flashback regarding how Nogizaka Haruka's parents ended up being together. Nogizaka Gento's younger version looks like "Neate Jamil" from the anime "Kidou Shin Seiki Gundam X". They both have that awesome sideburns and facial scar on the left eye, the only difference is Nogizaka Gento is wearing squared-sunglasses while "Neate Jamil" sports aviator-type sunglasses.

In episode 9 during the episode 10 preview (24.15-24.39), the silhouette woman refers to a seiyuu, Inoue Kikuko & her role as Kazami Mizuho in Onegai Teacher series. The '17' on top of her head is most likely referring to her self-proclaimed age, 'eternally 17 years old'.

In episode 10, Nobunaga tells Yuuto that he needs to know about five voice actresses. They all happen to be voice actresses for the five girls in the ending video. In addition, he warns Yuuto not to fall in love with a "super beautiful voice actress" by the name of Takagi Reiko. Of course, Takagi Reiko is Nobunaga.

In episode 10, during the after-recording of the "Nocturne Girls' School Lacrosse Club" 36th episode, Mizuki-sensei's character, performed by Kikuko Inoue, looks much like one of Inoue's most famous rôles : Mizuho Kazami, from "Onegai Twins!". What's more, Mizuki-sensei refers to Mizuho's famous gimmick sentence (always heard in "Onegai Twins" trailers): « This is priority #1 ». Shortly after, when Yûto gets his own copy of the script of the episode, on the cover are shown what should be the N's' true autographes (up = Mamiko Noto & Rina Satô / down = Mai Gotô, Kaori Shimizu & Kana Ueda).

In Episode 11, Nogizaka Gento is doing the famous "Gendo Pose". "The Gendo Pose" was made famous by the anime "Shinseiki Evangelion" via the character "Ikari Gendo". "Ikari Gendo" was voiced by Tachiki Fumihiko, he also voiced Nogizaka Gento in this anime.

In Episode 11, near the end of the episode, Sakurazaka Hazuki says: "Daitan'na...come here" (Daitan'na is a pun for "Daitarn"). This is a pun for the famous phrase ("Daitarn...Come here!") of "Haran Banjo" from the anime "Muteki Kyojin Daitarn 3", he calls his mecha "Daitarn 3" by uttering this phrase.