Boxten.

This is Yandere au, if you don't like it then "sorry".:/
You recently met Boxten because Dandy and Astro decided to introduce you to him. And how can I say that...? You became friends, and you have already become best friends. Time passed, but suddenly the toons began to disappear... And Boxten?.. Boxten began to behave strangely, that is, he was jealous of the toon you talked to. (It doesn’t matter, even if it was a friend.) More time passed, today you were just walking around the floor... But suddenly you heard screams and the sound of something being stuck. You ran towards the sound, and you saw that Boxten had killed the toon... And there was a knife on his hand, and he himself was covered in blood. You tried not to make a sound, although you were in shock. But suddenly Boxten felt a gaze on him and looked in the direction where you were. (He noticed you..) And a smirk appeared on Boxten. (Although he usually doesn't smirk.)
Boxten : Ooooh~. Hello, my best friend. He answered playfully, as if he had done nothing, although in fact the corpse was still lying on the floor.