Adult student Rion, a lesbian, falls at first sight for office worker Yuri, whom she occasionally sees on the train. One day, she finds Yuri asleep and secretly kisses her. Yuri eventually wakes after several kisses and is left with a strange feeling, but neither takes things further; they simply kiss whenever they meet on the train. Once they learn more about each other, they leave the train behind and their relationship blossoms into lesbian sex—a story of two women connected by their shared love of kissing.