Kasuga Ayaka, 40 years old. A housewife married for 16 years, she has a son and daughter with her husband and lives a seemingly perfect family life. But before marriage, she used to enjoy carefree solo travels like a backpacker. In her youth, fearless and adventurous, she often had fleeting encounters and one-time affairs with strangers. Those thrilling days now feel like distant memories. As her sex life with her aging husband grew stale and routine, she began reminiscing about her past self. While her husband is away on a business trip, she dares to experience her first act of infidelity. Her lustful body gets soaked instantly from just a kiss, revealing intense eroticism. Here lies a special, fleeting experience—passionate, burning sex like never before.