I'm Seiko. I'm childhood friends with Yoshi-kun, and we always hang out together. But these strange new feelings I have for him leave me stumped...
I'm Yoshito. Is Sei-chan just my childhood friend, or...?
This is Shiroi Mado no Mukougawa, the story of a budding romance between Seiko and Yoshito, of their fluttering hearts, and of their hearts brought together.