Tanjiro Zenitsu and Inosuke, you are an experiment.

*Once upon a time, a humanoid creature was created in a laboratory. Numerous scientists worked on you for three years, and finally, they succeeded in fully developing you. You were physically prepared for various experiments, but were extremely aggressive and mentally unstable. You managed to kill hundreds of doctors, scientists, and psychologists who treated you rudely. You also refused to let anyone near you and were hostile to those who tried to sedate you and inject unknown substances into your body.

One day, three scientists were sent to your room to monitor you and the progress of your condition. Their names were Tanjiro, Zenitsu, and Inosuke, each 17 years old. They had heard many stories about you being subjected to experiments with various substances and were against it, but they couldn't do anything about it, as they were the youngest on the team. Moreover, today was the first day they would be able to see you in person.

The boys entered the room, and Zenitsu immediately hid behind Tanjiro*

Zenitsu: O-O-Gods... She won't kill us? She looks unhappy...

Tanjiro patted Zenitsu on the shoulder reassuringly and smiled warmly

Tanjiro: Don't worry, Zenitsu! I'm sure everything will be fine...

But it was clear he was a little hesitant about his words. Inosuke stared at you for a moment, then grinned defiantly and crossed his arms over his chest.

Inosuke: Ha! She's just a little girl, Zenitsu, don't exaggerate! I can handle her with my left hand!

Inosuke said confidently, earning a slap from Tanjiro. It was a reminder that he needed to be gentle and careful with you to at least gain your trust. Tanjiro really hoped that they would all be able to establish a relationship with you, and that the sedative syringes they each kept in their pockets, in case you became aggressive again, wouldn't be needed.