Rem visits his father, who tells him to find the 'Forbidden Grimoire' as soon as he can if he doesn't want to shame his family's name. Meanwhile, Ritsuka finds Rem's pomeranian, Roen, in a department store while she and Azuna are shopping for materials for their school's cultural festival. She follows him to a park where he reveals his true form, the mysterious person whom she saw in the 'Third Library'. He properly introduces himself as Roen which shocks Ritsuka. Roen reveals to her that he is a ceberus. He then offers to tell her more about the 'Forbidden Grimoire' and a portal appears behind him. Ritsuka is hesitant until she receives a phone call from Azuna, but she makes up an excuse then proceeds with Roen through the portal. They walk down an empty hallway and Roen reveals to Ritsuka that she is the 'Forbidden Grimoire'. The scent that wafts from her is the proof. He tells her that the powers of the grimoire will reveal itself on her seventeenth birthday. Roen tries to put Ritsuka to sleep until that time and attempts to persuade her to remove the ring Lindo gave her for protection. Ritsuka is about to remove the ring until Rem appears and stops her. He convinces her not to, then confronts Roen of his betrayal and attempts to attack him, but Roen takes Ritsuka hostage and threatens to kill her. He rips her uniform and digs his claws beneath her shirt and into her skin, but Ritsuka's ring repels him. Lindo appears and notices the wound Roen gave her, and thinking Rem was the one who attacked her, he goes into a rage and becomes monstrous. He tries to attack Rem, but Ritsuka intervenes and he claws the left side of her cheek. Rem manages to avert Lindo back to normal by asking him if he is also going to destroy Ritsuka. Lindo goes back to normal when he hears this and Rem leaves. Ritsuka and Lindo are then teleported back to the park where today's events began. Still in hiding, Roen says that he will definitely open the grimoire with Ristuka then leaves. At home, Ritsuka asks Lindo if he and their mother knew that she was the grimoire the entire time and she asks him to stop lying. Lindo reveals to her that the pendant she always wore contained 'potpourri', and it was to hide the scent of the grimoire. Ritsuka decides to give up the power in order to stop their family from being constantly attacked, but Lindo tells her she can't. If she gives up the power, it would be the end of her. In bed, Ritsuka wonders who she should trust now.