Inkopolis News Studio
From Inkipedia, the Splatoon wiki
The Inkopolis News Studio is where the Squid Sisters film Inkopolis News. It is located in Inkopolis Plaza. It is next to the Battle Dojo and on top of Inkopolis Café. It cannot be entered.
Easter Egg
There is an easter egg here: if the player looks through the Studio's big glass window, the Squid Sisters will eventually wave at the player.