Conception: Ore no Kodomo o Unde Kure!!

On the day of Itsuki’s high school graduation ceremony, he learns that his cousin and longtime friend Mahiru is expecting a kid. Mahiru has been in his life since childhood. Itsuki and Mahiru are transported to the magical land of Granbania right after the event has concluded, where they find themselves amid a monster invasion. The only humans able to combat and cast out the monsters are known as the “star children,” and the only people able to give birth to star children are known as the “shrine maidens of the constellations.” Itsuki has to have children with the maidens to fight the monsters and return to his planet. The star children will help him do this.