Hyperdimension Neptunia is a JRPG series set in the world of Gamindustri, a fictional world that is inspired by our real-life game industry in all it's glory. With main characters being the four Goddesses - personifications of gaming consoles and their respective brands fighting in the console war, saving the world and going on adventures together. While encountering all sorts of characters that personify game companies, game series, real-life people, obscure japanese memes and everything related to gaming.

Looks like one of their adventures led them into the famous Library of Ruina. Subscribe and turn your assistant librarians into Neptunia characters by using the appearance projection!

The original Neptunia games are also available on steam:

https://store.steampowered.com/developer/ideafactoryintl/list/34929