Youkai Academy has been getting attacked by a mysterious organization known as Fairytale (an organization that our class' teacher Ryuu Higoroshi seems to know a lot about) that is lead by a dragon and whose goal is to destroy all humans. The first attack was one by a mage named Oz who blew up the teacher's lounge. Since a group of prefects was made in response, I assume that the attacks by Fairytale are known by the student body other than class 3C or are at least rumored (although since Elene, Lilizuki's former character and head prefect at the time, is gone, I don't know if the prefects are still a thing or if they have been retconned). You can only imagine the types of rumors that would be spreading.
Thus far, all other attacks by Fairytale have been countered by class 3C. A second attack by Oz was stalled by Nami, Takumi, Yorick, Gavin, Allister, Cheryll, Kakusu, and Sorae until Higoroshi-sensei arrived to repel Oz. Currently there is an attack by Divine, a mermaid, that is being countered by James, Sorae, and Chris (Cheryll, Yuria, and Marie are no longer in the fight but I'm not entirely sure that Marie counted in the first place since she wasn't exactly fighting Divine). There is also a battle between Solo the Lycan (a former student who joined Fairytale but betrayed them and is now being controlled by them to attack the academy) and Yorick, Nami, Takumi, Frio, and Elise. Allister was battling another Fairytale Lycan, Raka, secretly (thought it probably isn't secret anymore since his final attack before defeat was giant pillars of lightning coming from a spiral of storm clouds) but has been defeated and will be moved by Raka to a location where it would be difficult to find him. Genevieve plans to have Cheryll search for him.
Unrelated to Fairytale, Gavin doesn't believe the school has what it takes to defend itself without relying on class 3C which seems to be some sort of class organized specially for battling Fairytale so he went and started a forest fire to test the school's response. After fending off a pair of students believing him to be Fairytale, he fled into the forest. His current whereabouts are unknown. Another student, a Youko named Kakusu, has been suffering from a parasite that Higoroshi has been working hard to find a cure for. Higoroshi appears to be a skilled alchemist.
Other things to be aware of: There is currently a love triangle between Milly, Chris, and Sorae, and there is also a mutual attraction between Takumi and Nami. Marie also appears to be attracted to Yuria but judging by how quickly she became attracted to Divine then promptly unattracted to her (upon seeing Yuria), I'm not entirely sure what the deal is with that. Nobody, including the teacher, cares much about the homework thus far. Punishment for destruction of school property and for lateness both appear to be detention. The mall on school grounds appears to have just about anything that would be legal on a school campus.
The battle against Divine is occurring outside of the pool area where the students were having swimming class. Higoroshi appears to be entirely aware of the situation but believes that Divine wouldn't hurt his students. That is exactly what she is currently doing.
