A couple past their sixtieth birthday go on a long-overdue hot spring trip, rekindling their passionate relationship. Married for over thirty years, their daily lives had led to a sexless marriage. At the mixed-gender hot spring bath, seeing each other's bodies again for the first time in years reignites their desire, allowing them to enjoy intense, passionate sex just like in the old days. The warmth and physical intimacy they've missed for so long set their hearts ablaze once more.