Oono Nana is a high school girl whose heart easily flutters at the nonchalant words of the opposite sex, and she is very much aware of her "easy" disposition. One day, in the spark of the moment, she unexpectedly voiced her opinion out loud to Sudaka, the solitary yankee from her class.
She was expecting to be attacked for it but she received a confession from him instead. And now she keeps getting easily swayed by Sudaka's straightforwardness.