Two years after marrying a coworker and leaving the company, Kana still socializes with her former boss Arima and his wife. Arima invites both couples on a hot-spring trip, but Kana’s work-obsessed husband arrives in a foul mood, admits he never wanted to come, argues with her, and abruptly decides to leave. Hurt that he always puts work before her, Kana drinks away her sadness. The man who stays beside her and offers comfort is Arima, drawing them into an intimate affair.