Prison Lock and Grimoire Security

After Arin following Arata the whole day, he stops her to question what she was doing. Arin told the reason for following him is that she will be the Demon Lord's wife. Serina, Lilith and Levy, together with Arata, were suddenly trapped in his room by a seal placed on the room. While trying to break the seal, all of the girls start having the urge to go to the bathroom, which ensues panic. Running out of ideas, the group tricks the grimoire into telling where the seal was. Arin confesses to placing the seal and explains the reason for trapping Arata and the three girls in the room, before proceeding to use her spells to break the grimoire's control over Arata's power, creating the Black Sun Phenomenon, which is a Breakdown Phenomenon. Grimoire Security members Mira and Akio arrive and then proceed to attack Arata after a short conversation after learning he is the cause of the Breakdown Phenomenon.