On days when she’s feeling unwell, when she finds it bothersome to take care of class duties, or when she has scheduled tests… On days when she’s too lazy to go to school, I get called out. I am the double of Aikawa Sunao, a convenient substitute. We looked exactly the same, but our personalities were fairly different. I can’t go out freely, I can’t even make plans for tomorrow, I was a replica whose mission was to work for the sake of the original. I was supposed to be and yet, I fell in love. I fell in love with him, and for the sake of differentiating myself, I styled my hair in a half-up swept manner. I skipped school and went on a trip with only the two of us. And then, tomorrow, the day after tomorrow, and beyond that, we promised to meet. My name, my body, everything was a borrowed thing, I was supposed to be empty, however――this feeling of love, is mine alone. Occurring in a town by the sea, a very pure and slightly mysterious “first” youth love story shall take place.