Let's Try Giving Birth, Together

Itsuki finds out that in addition to Stardust Labyrinths where the "Impurity Lords" dwell, there is also the 13th labyrinth, as well as the existence of the 13th maiden. He sets out to find the maiden. However, there is the possibility that the 13th is a male. Although not quite convinced, he seeks all the male candidates he could think of...