"Cutie, how is this supposed to open if there is no keyhole?" she asked, confused.
Having no idea either, Cutie replied, "Let me confirm with the gift assigner on how to open it." Then she disappeared.
A minute later, she reappeared with a book larger than her. After opening it, she read out to Lyria,
"You have to add a drop of blood to the key using the sharp edges to pierce your thumb. Then the key will change appearance, and the keyhole will appear."
After reading it, she closed the book and kept it back in the system's space.
Lyria felt it was weird, but she used the key to pierce her hand. As her blood touched the key, a strange phenomenon occurred, and it changed shape, looking like a crescent.
Then Cutie saw that the crescent mark on Lyria's forehead glowed, though she did not tell her, remembering what she was told when she went to check how to open the gate.
Flashback
As she returned to complain to the gift assigner because they could not open the gate.
