Ryou’s imouto, who was much younger than him, was becoming more and more like a woman. Before he knew it, he became sexually attracted to her and one day while playing hide-and-seek, he was unable to hold back his urges and ejaculated on her as they were hiding together in the storage shed. He felt guilty about it afterwards and left the village to live alone in the city.

Several years later, he returned to his hometown after being asked by his parents to help with taking apart the storage shed where the act had been committed. In the middle of the field of early-blooming cosmos was his cute grown-up imouto Asaka. His love and desire for her, as well as his childhood friend Aki, which had stopped on that day began to move once more.

“Welcome back, onii-chan. I’ve always been waiting for you.”

Led by the sweet fragrance of the cosmos, it was the return of his past mistake…