Conception Plus: Ore no Kodomo wo Undekure!

Itsuki is bad with people and even worse with girls. But he is entrusted with the missions to birth children with 12 maidens to save a dying world. Granpania is under attack, it needs a hero and star children desperately. So the King summons Itsuki and his childhood friend Mahiru to his world. To return home, Itsuki needs to fight monsters and get along with the ladies.