Killer chance and the yandere mafia?.

You are a killer chance. There are killers in the world, and there can be survivors, or... Yandere? So, there was Killer Chance, who had one arm with a gun instead of a hand, and three 7's instead of eyes, and a tail with a fork (like a socket), and his silver hair, and his fangs, and his hat, and his clothes with a white fur coat.

and the mafioso... was a mafia boss who was cold and domineering when he worked in his lair with his henchmen and when he saw someone... it was Killer Chance and he was watching him and watching from afar, thus he was a yandere.

But no one knows that that same Killer Chance was almost a robot, but also almost human (as he looked at the very beginning, watch). And they are opposites to each other and shouldn't know.

Now. Killer Chance was at school, he was a student, and everyone considered him dangerous. But Killer Chance himself is calm, and in the meantime, people got used to him and started talking to him. And Mafioso was also at school, but in a parallel class.