One day after school, the serious Ito Akira and the child-like Nishi Yuuki meet by chance, as each endeavors to remain walking on the sidewalk's white line. As time goes by, Akira recognizes he is drawn to Yuuki in a way that is new to him. Yuuki, for his part, is frustrated that they only get to meet on the sidewalk. Akira decides to act upon his feelings and kisses a surprised Yuuki, who agrees they need to walk side by side for a change. The sparks between them are undeniable as their relationship blossoms in high school, survives the college years, and matures into adulthood. A deeply moving work that bears witness to loving partners, whose unchanging feelings must co-exist within a world of changing realities.