After his father remarries, Yuuta suddenly finds himself with a new stepsister: Saki, the greatest beauty at school. Neither of them is sure how to act around the other at first, but the two gradually grow more comfortable living together. Slowly, cautiously, patiently, two strangers become more. So...

After his father remarries, Yuuta suddenly finds himself with a new stepsister: Saki, the greatest beauty at school. Neither of them is sure how to act around the other at first, but the two gradually grow more comfortable living together. Slowly, cautiously, patiently, two strangers become more. So begins an unlikely love story.