A plain housewife in her fifties embarks on an affair that unfolds into a poignant, unforgettable story. Living her ordinary daily life, she finds her heart stirred by an unexpected hot spring trip with a stranger. She becomes giddy like a child, reawakening feelings of loneliness toward her husband. Never did she imagine the "Paradise Lost" she once romanticized in her youth would come to life. Internally, she murmurs, "I know I'm too old for such foolish behavior... but..." overwhelmed with guilt toward her husband. This illicit journey becomes a life-changing event that profoundly alters her existence.