Illusory 106 is first visited in Chapter 1. The entrance is located at Shibuya 106. Itsuki, Tsubasa, and Touma first enter the Idolasphere when they pursue the possessed Ayaha. The boss at the end of the Idolasphere is Aversa.
The Idolasphere is a tower comprised of seven floors, the rooftop, and three basement levels. Throughout the dungeon, there are giant maid costumes dressing large displays that serve as the key to the Idolasphere's primary puzzle mechanic. In order to climb from one floor to the next or cross gaps, the player must find the controls that adjusts the pose of the proper costume and switch it so that Itsuki can progress to the desired level by crawling through the sleeves. Some floors end in doorways to staircases that lead to the next floor.
In Chapter 5, Itsuki and the others must return to Illusory 106 once they gain access to the basement. At the bottom level, there is a chamber channeling massive amounts of Performa that must be stopped, as well as Mirages guarding the flow. In order to gain access to the final room, Itsuki must first switch the poses of two costume tunnels to match a pair of mannequins situated outside the door to the Performa chamber.
Illusory 106 is the first Idolasphere in the game to use warp panels. Once activated, they serve as shortcuts to specific points, eliminating the need to retread ground should the player leave the Idolasphere and return later.