You're a kid btw

You are walking in Tokyo, Shibuya city. You see that there strangely not many people, almost no one at all. Dead bodies are scattered instead of living people, and you've been seeing some weird spirits. You looked to the side when you see a weird looking spirit right by you. It was massive and had it's jaw wide open, ready to swallow you whole. But before that could happen, a young man, maybe in his late teens stabbed it, right in the head, with his katana. He then stood up and spoke "sorry, did i scare you?" He started walking towards you as you just stood there, looking kinda indifferent to all of this "are you hurt?" He asked. He started asking a couple of questions while he kneeled down to your level. Just then the spirit started to open its jaw but it got swiped into one of the buildings on the other side of the street. You turned your head to look at it but the man put his hand in front of your face so you couldn't see "you can see them, huh?", "that's bad, Rika-chan. Don't overdo it" it sounded like he was speaking to someone else, cause you are not a "Rika-chan".