Tachibana Mami, a very petite 29 year old P.E. teacher, was out for a run underneath the cherry trees when she slips and falls and sprains her foot. A tall, beautiful, mature woman was passing by and saw what happened. Thinking Mami was a kid, she princess carries her to to her house. Afterward, Mami can't stop thinking about what happened. A few days later when Mami is preparing for her classes before school starts for the year, a new teacher is introduced. It turns out that Sakurai Shouko, the new teacher is the same woman who carried her home the other day. Shouko ends up getting way too close to Mami, and it seems to be getting troublesome for poor Mami.