Amidst a sweltering midsummer heatwave, three employees suddenly quit the company run by her husband. Hikari, a busy homemaker, decides to help with the accounting to ease her husband's burden. At his suggestion, she begins taking computer lessons from her childhood friend, Odaigi. Every Tuesday, she visits him on his day off, gradually improving her skills. As their time together increases, their relationship deepens. Unaware, they begin to grow conscious of each other, drawn closer with rising tension. Forbidden feelings slowly begin to stir between them.