Mahiru receives a letter that Kuro quickly dismisses as being a prank. At a summer festival, Mahiru is approached by a stranger and asked to take a silver case to the lost and found stall, as the man had no time to do it himself. On his way, he meets a young man carrying a coffin who claims that there's a vampire sleeping inside it. An explosion occurs and Mahiru finds out it came from a case similar to the one he is carrying. He quickly calls Kuro to throw it into the sky, but it starts falling back too soon...