Seven years ago, four strangers pulled a ten-year-old girl from railway tracks just before a train arrived. That fleeting act of heroism bound a young office worker, a comfortable single woman, a freshly divorced man, and a charismatic young man in a memory none of them revisited. Now in 2023, Kasumi Kado, a 28-year-old office worker stuck in a rut, is startled to discover that the girl, now a 17-year-old named Amane, has reappeared in her life under disturbing circumstances. Amane has become entangled in a dangerous underworld, running a honey trap scheme and later taking on a dark part-time job to infiltrate the wealthy Yamasegawa household on orders from Chinese traffickers. To understand why Amane was forced into this life and to help her, Kasumi reunites the original four: Waka Sawagawa, a 34-year-old enjoying a carefree solo life; Ten Kimeruta, 28, who is newly divorced; and Nao Doujima, 25, the man Kasumi has long admired. Their reunion, initially meant to be a casual get-together, soon unravels each person’s hidden secrets. Nao begins dating a younger woman named Yumeka, who turns out to be pregnant, and a tabloid photo forces him to take refuge at Ten’s apartment. Ten himself becomes suspected of arson. Waka, after an encounter with her ex‑husband, is threatened with exposure over a past abortion and must deal with her son Wanri, who is also Amane’s friend and asks for help. Meanwhile, Kasumi, left in the dark, spirals into jealous paranoia about Nao. As the four adults navigate their own messy lives, they find themselves drawn deeper into Amane’s crisis, culminating in a tense standoff at a train station where Amane and Wanri escape the Yamasegawa estate and crash into Ten’s home, forcing the group to confront hard questions about responsibility, motherhood, and the value of a life played out in a society that judges every choice. The narrative weaves a suspenseful love comedy with sharp social commentary on pregnancy, abortion, and the quiet desperation of adulthood, building toward a final arc in which the four must decide just how far they will go to save the girl they once rescued.