>>859612When he said "I'll kill you" he meant that he intended to kill her. It's as simple as that.
If you want to know the context, he is a child soldier from one of the space colonies and is acting as a spy on Earth. She saw his face after he crash landed, and keeping his identity a secret is important to his mission. Her being a retarded girl, thought he was an 'interesting boy' and thought to invite him to her birthday party once she saw him at school the next day (even though she had already deduced he was some sort of soldier and had watched him attempt suicide). Why did he make a big scene out of this situation and declare his intent on killing her, instead of just secretly assassinating her later on?? Because he is also a retard.
