It was a dark and stormy day, everyone was out drinking and having a good time, everyone except for Kakashi.
Kakashi was bored out of his mind, he had been fucking with command prompt all day and hadn't gotten anywhere. He decided to leave the computer area, because apparently this is an alternate universe where ninjas have computers, and go make himself a milkshake.
The milkshake, it seemed, had the ability to refill itself, thus making Kakashi extremely happy.
The magic milkshake wanted Kakashi to drink it completely, for it knew it would never be empty, and it wanted him to die.
Kakashi decided to drink the milkshake and eat the cup.
It didn't work.
The milkshake expanded and began to destroy his internal organs until by a stroke of luck Iruka somehow managed to purge the milkshake from his body, with some sort of attack or something.
And to this day, noone knows why the milkshake wanted Kakashi dead.