As Dai-sensei takes over as teacher for Ayumu's class, she decides to put Ayumu through a trial, threatening to erase his memories should he fail. A class taught by Haruna soon comes under chaos when she accidentally creates a giant slime. Judging Ayumu's ability to handle the situation as a failure, Dai-sensei takes away Ayumu's memories. As Haruna, Eucliwood and Sera express their desire to bring Ayumu's memories back, Dai-sensei gives them the opportunity to dive into his consciousness and recover his memories. Finding a remnant of Ayumu's memories, the girls soon come across representations of Ayumu's various emotions, but easily beat them. They soon come across the representation of Ayumu's sloth, Belphegor, who takes over Ayumu's body. As Eucliwood confronts Ayumu in her Masō-Shōjo mode, she shows her all the notes she had written for him and, working with Haruna, manages to bring back his memories.