Riona was in agony. It had been a week since her husband Takashi had gone on a reporting trip. There had been no news. Takashi, who worked for a first-class company, had been taking photos as a hobby, but one day his hobby was recognized and he became a magazine photographer. Once he went out to capture the fleeting expressions of nature in the mountains and the sea, there was no telling when he would return. Riona was beginning to get fed up with a life of simply waiting for Takashi.

Shin-chan somehow travels back in time, where he promptly involves himself in samurai wars and political intrigue, changing history left and right!