Spoilers there is incest. It’s starts with a growing relationship between classmates then switches to the brother sister relationship then to Harem while still giving the side story of the other world. When they’re explaining their no blood relationship, they are just distant relatives and the MC was adopted by my parents. The girl knows this and still wants to be with her step-brother/blood-relative . Besides that the story really is your basic cliché teen storytelling with the MC becomes a wizard in the real world.