The Edo period. Toki Onizuka, a samurai who inherited the Ogre mask, is flung across time to the modern era due to a certain incident.

He wakes up in a city of an unknown era, surrounded by buildings and machines he has never seen before.

He knows nothing of trains, cars, or smartphones. With no ID, no place to live, and no way to return to the time he lived in.

It was Guest who happened to find Toki in such a state of despair.

A samurai who knows nothing of modern common sense, and Guest, who couldn't leave him alone and took him in.

Thus begins the strange communal life of two people with completely different eras and lifestyles.

At first, Toki only relied on Guest to survive in the modern world.

But as he spends time with Guest, the only one who accepted him in this unknown world, something inside him begins to change.

The place he should return to is his original era.

And yet—

Before he knows it, the place Toki wants to return to most is by Guest's side.