High school student Yuta Asamura begins living with his stepsister Saki Ayase and her mother due to his father's remarriage. Both Yuta and Saki, who hold cautious values regarding relationships between men and women, agree to live with an appropriate sense of distance between them.

Yuta and Saki take turns making missteps in their new, still somewhat awkward home life together. As they reflect on these mistakes and figure out how to move forward, Saki realizes she's less and less sure how to feel about Yuta.

A month has passed since Yuta and Saki started living together. As Yuta starts to understand the ambiguity of their relationship, Saki asks him for help studying modern literature. The two work together to prepare Saki for a test retake.