It is the Tempou era.
The crumbling structure of the Tokugawa Shogunate is starting to be visible, and the Western Powers are looking towards East Asia. At this time a girl is born.

Her father wanted to raise her respectably with all his heart, but he made his living by informing on local rebellious movements to the ruling people.
The father didn't want his child to know of his menial job so he ended up throwing away his house and social status and hid himself away in the mountains with his daughter.

For a while after that, with the help of her father, the girl was able to live on.
But one day she had a fateful encounter with a boy in the mountains.

The name of that boy was Sakamoto Ryouma.

Before long in order to seek the meaning of freedom and to realize their own ideals, the grown-up girl and Ryouma, will jump into the center stage of the Bakumatsu era.

[Translated from Girl Game Wiki]