Teko Saotome is a high school student thrust into an accidental time travel incident when Agino Jiro, a fugitive from the twenty-fifth century, commandeers the vehicle carrying her and her classmates along with their teacher. This event sends the entire group hurtling through various periods of Japanese history.

Their journey includes brief stops during significant events like the fire bombing of Tokyo, the Meiji Revolution, and the Battle of Sekigahara, all while evading relentless pursuit by a Time Patrol agent. The group eventually arrives in the Sengoku period, precisely four days before the assassination of Oda Nobunaga in 1582.

Confronted with critical decisions about altering history, Teko and the others grapple with profound moral and emotional dilemmas. A minor romantic subplot also unfolds for the character.

The story concludes as the group makes a final choice on whether to intervene, leaving the consequences of their choice to history.