Edit: apparently this is a very common form of Japanese storytelling called an isekai. There are 8 billion people in this world, no idea can be original. And sometimes you miss out on things many other people know. I’m clearly one of today’s lucky 10000.
Flat chested autistic girl here. Can confirm I’m in 3 harems with brave travellers from another world.
Congratulations on your success. Good luck defeating the demon lord or whatever evils plague your many lands.