*NOTE: Recommended level is 52.
Obtained: When Yashiro reaches Stage Rank 9, he will send you a Topic. When your ready, head to the Lesson Studio in Shibuya and speak with Yashiro.
After the cutscene, head to the Idolasphere in Daiba Studio. When you enter the Idolasphere, a brief cutscene will trigger. Yashiro will race on ahead so teleport to LCD Panels: Door 2 and enter Door 2. *NOTE: You will need to have Yashiro and Eleonora in your party before you take on the boss waiting on the other side of the door.
Upon entering the door, you will be challenged by Whampa (level 53) and Pale Warrior (level 51). Make sure to use Ellie and Yashiro’s new skills (The culprit is… and The clues…) against the boss. It’s a slow fight but each time you use the new skills, you do more and more damage. Have Itsuki focus on healing Yashiro and Ellie plus killing the Pale Warrior each time it spawns.
Defeat the Whampa to trigger a cutscene in which Yashiro earns a new Radiant Skill called Door of Possibility. Afterwards, head on over to the Bloom Palace to unlock it.