Really the only difference is how fast jap execs cancel stuff, how hard they expect an author to work and clear separation between the original work and everything else. You don't have issues where you'll be reading the main series only for you to then need to read three spin offs and then come back to the main work. Oh and clear genre and audience separation is a thing.Maybe the two sides of the Pacific aren’t as different as I thought.
Western Comics could stand to crib a few pointers from them. It would probably help sales.