Kasumi is in the midst of an affair with Ishiyama, one of her husband's clients. When Kasumi and her family visit Ishiyama's villa in Hokkaido, she plans to abandon them to be with Ishiyama. The next morning, her daughter Yuka disappears, which throws Kasumi's life into turmoil. Years later, Yuka remains missing, and Kasumi journeys back to Hokkaido with Utsumi, a terminally-ill former detective, and tries to follow any leads she can.