Haganai/Shout-Out

"Sena: "Once I become an overnight star in the voice acting world, I'll become great friends with Minori Chiharu-san who voices Yuko, and Kusasawa Kanako-san who voices Dark Cat .""
 * The main trio play an RPG called Monster Hunter.
 * Tokimeite Memorial Days is an allusion to the Tokimeki Memorial series. In that game, there's a background character who seems like an Expy of Ryoko Asakura, a heroine named Akari |Fujibayashi, and another heroine, Yukiko Nagata -- an obvious expy of Yuki Nagato.
 * The fights between the chibified Sena and Yozora in the pilot and Chapter 11 are blatant shout-outs to The Powerpuff Girls.
 * The Eroge Sena was playing is an obvious adaptation of The Sacred Blacksmith.
 * The Pari-den manga Kodaka reads in Chapter 13 features a character with a ripoff of Grevil de Blois' hairdo.
 * In Chapter 14 Sena's playing Love Plus, apparently romancing fellow Ojou Manaka Takane. Rika's also a fan of Gundan, OVA, and mentions the series' appearances in Ultra Mecha Wars Alpha 2.
 * The recently released Drama CD involves the club members as voice actors for an RPG whose characters were based on their likeness. Then we get this one-liner from Sena:

"Rika: "Just as planned.""
 * Turns out the game they were to have voice roles in -- Heaven of the East -- is actually an eroge, and everyone is not happy that Rika didn't tell them. Cue Rika's reaction:


 * There's also the obvious Squid Girl, A Certain Magical Index and Angel Beats! Shout Outs.
 * In Chapter 15 of the manga, Sena laughs off at Kodaka introducing Kobato to the Club, assuming the iconic Kirino-with-Kyousuke-from-behind pose (with Rika in Kyousuke's position) and claiming "There's no way your little sister can be this cute!" (May also count as a bit of Actor Allusion, with Kobato sharing the same voice actress as another Elegant Gothic Lolita from said show.)
 * Kobato also claims to be a True Ancestor.
 * In an extended reference to Kobato's voice actress's most famous role as Kuroneko, "Kurogane no Necromancer", the goth-loli anime Kobato watches, closely resembles "Maschera", Kuroneko's own favorite show.
 * When Yukimura bumps into Kodaka (who deliberately did so in order to catch his "stalker"), the former gives him his wallet with a decoration of six coins arranged in two rows of three, alluding to his namesake, the famous samurai Sanada Yukimura, who used it as his family crest.
 * In the virtual game in episode 5:
 * Rika's virtual avatar is dressed like Rikku
 * Maria's looks like Index, which Kodaka lampshades.
 * Sena's blacksmith outfit is quite close to the one from Ragnarok Online. Unfortunately, she was thinking of The Sacred Blacksmith when she selected this class, as her description of the role reveals.
 * The game itself: it's called Romancing SaGa XIV, runs on LargeHard's hardware, is missing lots of features and abuses re-uses of models.
 * A popular meme on Japanese Message Boards is that an Otaku becomes a wizard if he stays a virgin until age 30. Guess what Kodaka's mage outfit is... (see also Take That)
 * On Episode 11, during Rika's reminisces on the Comiket, one scene clearly shows what looks like Kyousuke, Kirino, Kuroneko and Saori.
 * At the festival in the same episode, some of the masks from the stalls are from Goseiger.
 * The BD edition of Episode 4 recolors Rika's imaginary spacesuit to resemble Asuka's experimental EVA-02 plug suit.