In the first episode, all first-year students have to wear cat ears on their first day at school. If I remember correctly, the other students are trying to catch anyone wearing these ears.
The main character is a teenage boy who is wearing cat ears. I think they were calling out “nekomimi” while searching for him. He’s running around the school and eventually finds a big cage. Inside it, there’s a tiny yellow animal that looks like a chick. It’s really small and cute, but it has an angry expression, like a red 💢 mark on its head.
The boy gives the little animal some food crumbs. After a while, a few bullies try to catch him, but the tiny creature gets out of the cage and beats them up.
Later, I remember the main character meeting a girl who was sitting under a tree, reading. I think he had a crush on her.