In a side-story of Darker than Black, known as Episode 26, unfolding alongside Kuro no Keiyakusha, the Syndicate tasks Hei and his team with a new mission. Their objective? Retrieving the valuable belongings of a deceased contractor rumored to be hidden beneath a cherry tree. As Hei delves into this mysterious assignment, Misaki Kirihara and her team prepare for a visit to the Cherry Blossom festival, unaware of the secrets lurking beneath the blossoms.