Fia, who is aiming to be a knight in a family of knights, remembers her previous life as a "Grand Saint" when she was on the verge of dying. The saint is currently a highly important and respected profession because and is on the verge of extinction! The holy power she can use happens to be the "lost magic" of myths.

In her previous life, she was threatened by the right arm of the Demon King, saying, "I'll kill you again if you're reborn as a saint."

"If I use such power, I wonder if I would be caught and killed once again…"

Watch as she tries to live a simple life as a knight, hiding the fact that she's a Grand Saint!

Hakushaku is the 5-year-old male tortoiseshell cat in residence at the Fujiwara home. He has a tough job trying to keep the two daughters, Shizuka and Yumeko, in line, and he often ends up suffering for his efforts. Shizuka is a high-school-age girl who has stopped going to school and has become a shut-in. Hakushaku tries to encourage her, but sometimes he has to stop her from doing embarrassing things, like showing her boobs on the internet. Yumeko is the younger sister, a middle school girl who has a huge crush on Shizuka. Hakushaku doesn't know how to handle this sister complex! A cat has a hard job in a household with such unusual girls!

The duty of a Grim Reaper is to end life, but this one falls in love with a human and commits the greatest taboo of his kind. How real is this love between "death" and a young boy?