Saikyou Kenja Fuufu no Kozukuri Jijou: Honou to Kouri ga Awasattara Sekai wo Sukue Masu ka?

The Suzaku and Byakko clans have been locked in a long-standing territorial war. Their leaders, Shiranui and Aura, have clashed many times, with each battle ending in a draw. A shrine maiden delivers a prophecy to Shiranui: in order to prevent the world's destruction, he must marry Aura and bear a child with her, for the child is destined to be the world's savior. Though beautiful, Aura knows nothing about relationships or reproduction. By day, the two remain enemies and warriors; by night, they attempt to fulfill the prophecy, learning about intimacy in hopes of conceiving.