Alright, my figuring is that if this is a mash-up world with all of our individual animes happening simultaneously on the same world, our character's roles in their specific animes are such that they would be oblivious to the goings-on of the other characters, while acknowledging and understanding that the world is vast and variable, which is why they all seem to come from different worlds and don't question too much how mages, ghosts, angels, mechs, aliens, magical girls, and mechanically enhanced body parts can all exist in the same timeframe and area, hence the lack of acknowledgement of the bizarrely varied cast of students in both clubs. For example, like TK said, Arthur and Jem likely don't watch the news because they're too occupied with their magic and sword fighting. Sayuri and Jonathan would know nothing about each other's lives because both utilize magic in some form, but Sayuri's anime is a predominantly magical one while Jonathan's is more military and tech based. All of them can exist in the same world (with one of the linking factors being magic) while all of them being entirely clueless as to what their clubmates' (being non-canon to their individual stories but possible to exist in the same universe) lives are like because they don't experience that part of the world.
