My Happy Marriage, Vol. 6 (Light Novel) - Akumi Agitogi

Kiyoka has been imprisoned, and Miyo takes it upon herself to rescue him by whatever means necessary. But when she arrives at military HQ, she comes face to face with a stunning young man...who looks exactly like Kiyoka. Claiming to be Kiyoka's familiar, he takes Miyo back to the Usuba household where she decides to turn over a new leaf-by carving her own path to reuniting with Kiyoka.