RIENE561 When two friends, a man and a woman, who have always talked

When two friends, a man and a woman, who have always talked about keeping each other chaste until marriage, enter an open-air bath for the first time alone together, will their sexual desires prevail over their friendship?

「結婚するまでお互いに貞操を守ろうね」と常々話していた友達同士の男女が初めて2人きりの混浴露天風呂に入ったら友情よりも性欲が勝ってしまうのか？