Conception PLUS Maidens of the Twelve Stars — the main character, Itsuki Yuga, is suddenly summoned to the magical world of Granvania to save him from evil forces. As a savior from another world, Itsuki and his Star Children conceived by him with a dozen Star Maidens are the only ones capable of casting out this evil. To return to his world, he must save this world with the help of his Star Children.