After the chaos of the Harvest Festival, Welcome to Demon School! Iruma-kun shifts into the school year’s next big flex: the Music Festival. And according to Anime News Network’s review of volumes 17-20, this arc is not just another “class performance” storyline. It is where the Misfit Class finally has to deal with a student most of them barely realised existed.
The setup is classic Iruma-kun school-anime pressure. Most of the Misfit Class managed to climb in rank after the Harvest Festival, but not everyone has reached dalet yet. That matters because the class needs to keep proving itself if it wants to hold on to Royal One, their ridiculously prestigious classroom.
At first, the plan is to centre the performance around Elizabetta, who appears to be the only remaining rank 2 student. Then Kalego drops the actual bomb: there is another rank 2 in the class — someone the others have basically overlooked.
That student is Soi Purson, the thirteenth member of the Misfit Class.
Sharp fans may already have noticed him hiding in plain sight, and the review points out that his existence fits the series’ love of numbers like thirteen and 666. But for the characters themselves, Purson’s reveal changes the whole vibe. He is not just a gag about invisibility. His family specialises in staying unseen and avoiding detection, but Soi himself is not fully comfortable being treated like a shadow forever.
That is where this arc lands surprisingly hard. Purson wants to play music. He is good at it, and he enjoys it. The problem? Music means performance, and performance means being seen. For someone raised to disappear, stepping into the spotlight is not just scary — it goes against what his family expects of him.
ANN’s review highlights that Purson’s conflict with his father becomes one of the emotional cores of these volumes. His father would rather have him leave school than perform, which turns the Music Festival into more than a class assignment. It becomes Purson’s first major push to decide who he wants to be.
The performance piece, “Lilith’s Carpet,” also seems to be a major highlight. Kalego frames the story as one about a beautiful demon woman using her charm over men, but Iruma and Purson interpret Lilith differently. Instead of treating her as an object of desire, they see her as someone overwhelmed by attention she did not ask for.
That reading gives Elizabetta more dignity than simply being “the attractive one” in class. It also mirrors Purson’s own situation: both characters are trying to define themselves outside of what other people project onto them. That is very Iruma-kun — soft, funny, chaotic, but quietly serious when it wants to be.
Analysis for Malaysia/SEA readers: this is the kind of arc that matters if you follow long-running school fantasy manga for character payoff, not just jokes and power-ups. Purson’s story taps into something pretty universal for SEA fans too: the pressure between family expectations and personal passion. No need to oversell it — that theme hits because it is simple, familiar, and handled through a character who literally has to choose whether to remain invisible.
The review also notes that Osamu Nishi uses these volumes to seed future problems. Asmodeus starts looking at Kiriwo differently after training with Balam, Poro-chan may become more serious than the earlier comedic impression suggests, and Iruma’s secret — that he is not actually a demon — remains a ticking danger the more people discover it.
The main downside from ANN’s review? Not enough Ameri or Clara. Fair complaint, honestly. But if Purson’s arrival gives the Misfit Class a fresh emotional angle while making the Music Festival pop, volumes 17-20 sound like a strong stretch for Iruma-kun fans.
The manga is credited in the source as translated by JM Itomi Crandall and lettered by Phil Christie.