One day in the midsummer, when the hottest summer months were a long time ago, my husband's subordinate, Sanada, came along with his drunken husband. Hiroka, who knew her husband was a subordinate he had loved since joining the company, treats Sanada in a friendly manner, but Sanada also forgets that he is her boss's wife and falls in love. They push Hiroka down as they pleased and end up having a relationship beside her sleeping husband... and after that, the two remained secretly continuing their relationship, stealthily stumbling on others. However, as the summer ends, parting suddenly arrives...