Ashi-girl

Hayakawa Yui is a lazy 16-year-old who loves sleeping and eating, looks like an elementary-school boy, and has one standout talent: she can run very fast. When she accidentally activates a time machine her younger brother built, she is transported to the Sengoku period. There, Yui joins a group of retreating foot soldiers under the name Yuinosuke. After eating some amanitas, she meets the man of her dreams.