What...?

Walking into a typical school, Cleber, a slightly overweight young man with short black hair and dark circles under his eyes, heads to his classroom for the first class. Having recently enrolled in high school and noticing a nearby public school, he applied and passed the test with a little effort.

-- Aaahhh... So sleepy... -- Cleber mutters as he locates his classroom.

Peering inside, he observes a few people taking their seats. Without much thought, he chooses a nearby desk and sits down, anticipating the arrival of both students and the professor.

-- Ei, my friend, it's better not to sit here. -- someone calls out from behind. Cleber turns to find a black, muscular guy with an unusually large mustache.

Why did you grow your mustache so much?

-- So... Why can't I sit here?

-- It's because... It's dangerous.

-- How!?

Isn't he also in the first year? How can he say that?

Approaching Cleber, the muscular guy said, attentively scanning the surroundings:

-- ... Did you come to this school without knowing?

-- Without knowing what!?

-- Well... There's a rumor that in the fifteenth desk of classroom 1-B, if a guy with messy black hair, dark sleepy eyes, around 1.68m tall, blood type B, a bit overweight, and inattentive sits down, that person might become...

-- What kind of ridiculously specific explanation is that!? And what do you mean by "become"!?

-- ...You know, it's just a rumor anyway. Nice to meet you, my name is -

-- Keep going with that damn rumor!

-- Silence for a minute!

Upon hearing this, Cleber looked to the front of the room and saw that his teacher had just entered. An elderly man with white hair but who still seemed quite lively.

When Cleber turned his gaze back to the guy who had approached him, he noticed that person had already sat some distance away.

-- It's been a while since the bell rang, and everyone should have arrived... If someone is missing, please pass on the information I'm going to write on the board.

With that said, the teacher began addressing topics related to the school, exam system, daily subjects, and other relevant matters. Cleber wasn't paying much attention, as he knew that, overall, it was always the same explanation. So, he decided to look at the student next to him and saw... a corpse.

Is that person dead!? How can someone so pale and fragile exist!?

Observing the person's appearance closely, Cleber noticed the long blonde hair that reached the waist and a face resembling that of a beautiful girl. Cleber wanted a better view, but she was with her forehead on the desk, lying down while her arms were on each side of her head.

-- ...What's up with this person? -- he wondered, unsure how to react.

Turning to the other side, Cleber saw an expressionless girl, silently jotting down what the teacher was saying.

-- Why do I have the slight feeling that I'm in a strange school...

And, finally, a caramel-colored dog entered the room during the explanation and, without seeming out of the ordinary, sat in a vacant desk and looked toward the teacher.

-- ...Why does that dog have a seat!?