Yui Hayakawa, 16 years old. She is a high school girl whose only strength is her running skills. One night, his younger brother, Takeru, builds a machine that sends her back in time to the Warring States period. Yui desperately joins the foot soldiers and passes herself off as "Yuinosuke". A handsome young warrior appears before her, and she falls in love with him at first sight. He is the legitimate heir of the Hagi family, Kuhachiro Tadakiyo. As it happens, Yui finds herself staying with Yoshino, a farmer. She goes to the castle with the sole intention of seeing Tadakiyo again.

Yui is a high school girl who travels back in time and finds herself in the Warring States period. While she is disappointed that she cannot meet the Young Lord Tadakiyo, she hears about a "footrace" between retainers. Yui appealed directly to the retired Nobushige of the Amano family. She participated in the footrace competition. In the end, she was unable to become a foot soldier and returned to Yoshino. Unable to give up, Yui meets Tadakiyo's older brother, Naruyuki. She was told about Tadakiyo's fiancee, Ako...