A secret society at Iris Academy.
Some spoilers ahead.
To become a full member:
- Keep a positive relationship with Ellen and go to the play when she invites you.
- In the conversation after the play, choose revenge.
- Don't plan to study or sleep on December 4th.
- [unsure] When Ellen fails her exam, don't tell her it's unfair. If she fights with Grabner, she will be invited instead of you.
- On December 3rd someone will try to initiate a magical communication with you to invite you to a meeting.
- Go to the meeting, agree to join, perform the task.
- Whether or not you tell Ellen the truth has no effect on being made a member, but it will affect your relationship score with her.