Obake is a Japanese word that means a ghost or a monster. It's kind of like a creature that people think is real, but they can't really see it. Imagine a scary Halloween costume that someone wears to scare their friends. That's kind of what an Obake is in Japan.
Sometimes people tell stories about Obake to scare each other or to explain strange things that happen, like if something goes missing and they can't figure out where it went. They might say that an Obake took it.
It's important to remember that Obake are not real, even though people in Japan might talk about them like they are. They're just part of Japanese folklore and culture.