Ichiko and Otoya have been married for 7 years, but unknown to others around them, they are in a sexless marriage, have no children, and share a secret: on the third Thursday of every month, they have an agreement to let Otoya spend the night with his "lover". (Source: Drama-Otaku) Adapted from the manga series "1122" (１１２２) by Watanabe Peko (渡辺ペコ).