The time is the Taisho era.

The orphan Meiko, who suffers from weak eyesight, lives a modest but peaceful life at a temple orphanage.
One day, a suspicious person visits the temple and suddenly attacks Meiko.

When she wakes up, she finds that time had rewound several months back. To avoid death, Meiko follows a guide.
There she meets her long-lost twin sister, Kanako, the daughter of a marquis...
After her parents tell her the story of her birth, Meiko is to marry Matsuwaka Akashi, a military man feared as the [Demon Akashi], as Kanako's substitute-

A tale of two people who had an unhappy fate but found new happiness.