Lost Paradise tells the tragic tale of two lovers whose passion burns so intensely it destroys them. Based on the bestselling novel by Junichi Watanabe, the story revolves around the fated love affair between Shoichiro, a middle-aged man who regrets dedicating his life to work, and Rinko, a beautiful woman trapped in a marriage filled with depression and disillusion.
A man engaged to Shoichiro's daughter, Chika, falls in love with Rinko, prompting Shoichiro to meet with her and ask her to end the relationship. Despite their initial unpleasant encounter, Shoichiro and Rinko soon find themselves drawn to each other, discovering something missing in their lives. Their passion intensifies, leading to a yearning for everlasting, perfect love that ultimately results in a fateful decision.