Sharing Life With Each Other

Nathan is living on a world where better intellect means better achievement and where peace is everywhere. A world where magic don't exist. Being bored in his daily life as a student, he prefers to live in a fantasy world.

Eula is living on a world where stronger means better achievement and where violence is everywhere. A world where science don't exist. Living in the midst of a war, she wants to live in peace.

When both of them are presented an opportunity to live in each other's life for the sake of experiencing their preferred life, they are delighted since they can go back and forth as they desire. Upon discovering that there is a time limit, they need to extend it by meeting with each other. How hard can it be?