Second doujin detailing Okuu and her daughter as done by various artists.
The title is based on the Japanese fan term for milf Utsuho, 良妻空母 (ryousai kuubo), punning ryousai kenbo (良妻賢母, "good wife and wise mother") and kuubo (made off her name, Reiuji Utsuho 霊烏路 空 and "mother" 母). More info (in Japanese) at Pixipedia.