Toshiki works at a construction company. On his day off he helps his boss move into the apartment across the hall. The boss’s wife turns out to be Himari, a former colleague he once had feelings for.
He starts secretly watching her daily life from his window. At the same time, Himari is sexually frustrated in her marriage.
A few days later she realizes he is peeping, and the distance between them gradually closes until they begin a forbidden affair.