Mita Sakura is considered to be weird by her colleagues at the Tokyo Metropolitan Police Department, because she voluntarily works in the unidentified bodies department. About 20,000 unidentified bodies exist in the country and Mita Sakura works on returning these unknown deceased people to their families. She has a colleague, Tsukimoto Makoto, who works in the same department. They are totally opposite in terms of their personalities and interests. Mita Sakura is bright and warm-hearted, but Tsukimoto Makoto is calm and cold-hearted. They do share the same desire to return these unidentified bodies to their families. To find the identities of these deceased people, they rely on the few clues that are left behind on them.
Shiino one day finds out that her best friend Mariko has committed suicide. After snatching Mariko's urn from her abusive father, Shiino heads to Marigaoka Cape, a place Mariko always wanted to go.