The names of the The Oracles are based on the nicknames for console fanboys in Japan.
Jinguji Kei is a reference to the Sony Playstation, Chika Hakozaki is a reference to the Microsoft Xbox, and Mina Nishizawa is a reference to the Nintendo Wii.

Uni's name is taken directly from the "Uni" in "Universal Media Disk", the type of disc used specifically by the PlayStation Portable.

During the game's True Ending, an image of the game's cast is shown; upon closer inspection, Uni has six fingers instead of five. This was later corrected in the game's official art book, but is still visible in-game.

Ram and Rom's characters are influenced by Nintendo's Ice Climbers (Nana and Popo), based on the colors.

5pb. is named after a Japanese music and game manufacturing company, with her headphones being based on the company's logo. Her Japanese voice actress, Nao, is a musician under 5pb.'s record label, as well as the singer for "Ryuusei no Bifrost", the opening theme to the original Hyperdimension Neptunia.

Several of Gust's attacks feature characters from the Atelier series.

5pb's special attacks feature characters from Steins;Gate.

The DLC character Cave uses scissors as a weapon, a reference to the character Casper from the iOS game Deathsmiles, which was developed by CAVE Co., Ltd., the company whom Cave is named after.

After winning a battle, there is a chace that Neptune will sing the victory theme from Final Fantasy.

Falcom published books under the alias A. Christin. This is a reference to Adol Christin from the Ys series, as well as her character design being modeled after said character.

Blanc is also a big fan of her books. This is likely a reference to how many Falcom games were on Nintendo consoles.

Several of Nisa's special attacks summon characters from the Disgaea series.