Generally, the security at campus concerts is quite good.
They're vigilant against people, and even directors from the student council have to show their ID multiple times before entry. Not to mention those without credentials. But nobody expected a cat to suddenly appear.
Cats, sometimes, you just can't guard against them. A moment of inattention, and there they are, making their presence known.
With such a big event and so many people, the deafening sound effects, and the cheering crowd, most animals would stay far away. Unfortunately, sheriff was an exception, and of course, it might also have been because the venue had quieted down a lot, plus Jin's playing of "Cat's Fantasy" had attracted the cat.
