Densha no naka dake shika awanai: Watashi no kuchibiru (Chu!) Furendo

電車の中だけしか会わない　私の唇（Chu！）フレンド

Also known as BOKO-019

Rion, a lesbian student, falls in love at first sight with Yuri, an office worker she only encounters occasionally on the train. One day, seeing Yuri asleep, she secretly kisses her. As the kisses continue, Yuri begins to notice and feels a strange mix of emotions, though their bond remains limited to these train encounters. Once they learn more about each other, they leave the train and their relationship evolves into lesbian intimacy, a story of two women united by their love of kissing.