Rio Ozawa (Nozomi Sasaki), a beautiful 17-year-old high school student, is emotionally detached due to a traumatic past, making it difficult for her to form genuine connections with others, engaging in compensated dating and manipulating those around her for financial gain. When Rio picks up photos she had taken at a photo studio, she realizes that they're not hers – they got mixed up with Kouki Ozawa (Shosuke Tanihara), a 35-year-old college professor, due to them sharing the same surname. Upon meeting Kouki, Rio falls in love for the first time, triggering a dramatic change in her personality and lifestyle as she tries to attract Kouki's attention. While Kouki is interested in Rio, he's secretly dying of brain cancer, causing him to keep Rio at a distance and eventually disappear from her life. Will Rio and Kouki find a way to overcome this, or is their love doomed from the start?