Here the protagonist has to die before they can be reborn in their fantasy world, which has become the norm for modern Isekai stories. But The Brothers Lionheart stands out as adhering more closely to the Isekai idea, since in this case it's not about stepping through a magical door.

More examples of older literature that uses the same narrative idea as the Isekai would be Alice in Wonderland or The Chronicles of Narnia, among others. The book is considered one of the classic Swedish children's books, like many of Astrid Lindgren's works, although this one got some criticism because in a way it glorifies suicide, and presents death as a way for a sickly child to escape to paradise.

In this world his brother has already arrived before him and made a name for himself as a hero, and we now follow the younger brother as he attempts to reconnect with his brother, become a hero in his own right, and save the world from an evil warlord. Shortly after the younger sickly brother dies as well from his disease, and he wakes up and finds himself in Nangijala like his brother said, in a magical fantasy world. One day a fire breaks out in their house, and the older brother dies while trying to save his younger brother. In The Brothers Lionheart we're introduced to a sickly 10 year-old boy who's dying, most likely from tuberculosis, but his older brother reassures him by telling him that when people die they go to the magical land of Nangijala.

The brothers lionheart