Three friends from college are now on the brink of turning 40. To attend a funeral on Jeju Island, they go on an unexpected trip as a getaway and wind up at a guest house, where water shimmers, wind blows, and pretty women are seductive, inviting the trio back to their 20s.
평생동안
Kang Shin-Woo is a math teacher with a good looking appearance. He has not forgotten his first love Han Ji-Soo for the past 10 years. By an accident, he travels to the past when he was a high school student. There, he meets his younger self. Kang Shin-Woo struggles to make the younger Kang Shin-Woo's love come true.
KDI-109, a male robot from the future, comes to live with Shin Ki Won's family. She is a girl who is studying in the philosophy department.
