Several of those are anime, so why is anime listed as it's own thing? Separately, when did everyone switch from just liking something to being in "fandoms". I mean, I'm a pretty big Trekkie and have been for a long time, but I certainly wouldn't describe myself as being in a Star Trek fandom.
Anime - Japanese cartoons. No real particular style to them as it's changed appearance over the decades and different artists do different things.
Pokemon - An anime that started as a companion series to a children's video game for the Nintendo Gameboy about capturing and battling monsters.
Hunger Games - Young adult novels turned into movies about a society that pits teenagers against one another in a giant death match every year.