The Deviculum Arc is the 19th Story Arc of the Welcome to Demon School! Iruma-kun manga series.
The arc centers around Ameri's father, Henri, bringing his daughter along to the Deviculum party; an event for high ranked demons where Ameri could potentially further her future career meeting so many established demons. Ameri remains uninterested in the event due to it getting in the way of what would have been a day with Iruma. However, it comes as a complete shock to her when it turns out that Sullivan has brought Iruma along to attend the Deviculum. The two of them end up dancing together on the staircase outside the Deviculum, much to their enjoyment.
The arc consists of chapters 179 and 180.
Deviculum Arc Summary
Chapter 179: One Year's Distance
Ameri does her daily routine where she patrols the halls as the proud and dignified Student Council president. Once she's returned to the council room however, her more womanly persona kicks in over being excited that tomorrow, she's finally having another reading session with Iruma after the two of them have been busy for so long. Ameri leaves a message to Iruma ready to see him tomorrow, and prepares the council room for the reading session, but she also pouts that Iruma turned down hanging out with her in order to celebrate with his class regarding their Music Festival success. Ameri thinks over how it looked like the Abnormal Class was all having fun during the festival, and that for her, the only times she ever has Iruma to herself, as well as being herself, is during their reading sessions.Suddenly, Ameri gets a video call from her father, Henri, to invite her to a certain event. However, said event is going down at the same time as her reading session with Iruma. Ameri tries to turn down the invite since she already has plans, but Henri informs her that the event is the Deviculum party; an event that only the highest ranked demons are allowed to participate. Henri continues to explain that Ameri attending the Deviculum is essential if she truly desires to help with his work in the future, and asks if her ambition is so weak that she would let such an opportunity slip away. Not wanting to back down on her ambition, Ameri agrees to go to the Deviculum, and has to message Iruma that they can't do the reading session. Feeling gloomy, Ameri's left wondering how much closer she could have been to Iruma had she been in the same class as him instead of a year older. Sitting on the floor, she says to herself that she wants to see Iruma.
The next day, a dressed up Ameri arrives at the Deviculum with her father, which the two of them are greeted by fellow high rank demons. While talking with said demons with her father, Ameri sees some of them dancing, and thinks of Iruma as someone she wants to dance with. Suddenly, one of the high rank demons asks Ameri for a dance, which she swallows her pride to go along with it given her status. As she's about to take his hand, however, a loud commotion is heard due to the notable arrival of a certain group of people. Said group turns out to be Iruma alongside Sullivan and Opera. Iruma, who's dressed up like a noble, approaches Ameri and kneels before her asking her to a dance, much to her surprise and shock.
Chapter 180: A Centimeter's Distance
A flashback is seen where Sullivan got word of how Iruma's daily plans were cancelled, which Sullivan offers to take Iruma to the Deviculum. Jumping ahead, a dressed up Iruma stands alongside Sullivan and Opera at the Deviculum, which the excited Iruma first goes for the food. Opera notices Ameri nearby about to be asked to a dance from a high rank demon, and informs Iruma that she's here. As Iruma's about to head off to say hi to her, Opera holds him back as he needs to quickly learn the proper greeting etiquette for such an event like the Deviculum. Returning to the present, Iruma shows off proper etiquette kneeling before Ameri and asking her for a dance, which the shocked Ameri is unable to understand how Iruma's here. Henri catches sight of Iruma with his daughter, but before he could confront him, he's greeted by Sullivan, who uses the moment to brag about his grandson achieving Rank 5 (He).Due to the attention being brought by his grandfather, Iruma pulls Ameri along to take her elsewhere. Iruma brings Ameri outside to a fountain in front of the Deviculum where he attempts to dance with her. However, he ends up struggling due to having never danced before, and apologizes for his incompetence. In return, Ameri laughs it off as something she expects from Iruma, and offers to teach him. Given their height difference, Ameri and Iruma go to the stairwell that leads up to the Deviculum. Iruma takes the higher stair, which with Ameri's teachings, the two of them happily go about dancing together on the stairwell. While dancing, Iruma mentions how he's been thinking about what Ameri is to him. That Ameri is someone who makes him want to do his best when she's with her, and that she showed him a goal to aim for. Thus, Iruma states that he believes that Ameri is someone he wants to get much closer to. Iruma's words leave such an impact on Ameri that it causes her to hug him; claiming that she was thinking the exact same thing towards Iruma all this time.
Realizing that she's hugging Iruma, the embarrassed Ameri quickly backs off while trying to explain that it was just a reaction from Iruma praising her. However, Iruma is left silent and blushing at Ameri's action to hug him, which causes Ameri to blush in return unable to handle Iruma's reaction. Suddenly, Sullivan, Opera, and Henri arrive to take the two of them home. The next day at Babyls, Ameri's back to her hallway patrolling. However, seeing Ameri smiling and happy, the students discuss how she seems to be appearing more radiant than ever. Meanwhile, Lied walks with Iruma asking if the latter found the answer regarding Ameri possibly being another of his "soulmates." However, the embarrassed Iruma answers that he's confused as ever about it.
