Touno Bijutsukan
Do not open the door of the museum at night—.
Detective Miki of the Kita-Akasaka Police Department visits the Tono Museum of Art, where "strange rumors" are whispered about, to investigate a case of theft. While searching for Kanae Tono, the director of the museum, he witnesses a young man falling from the roof. Feeling uncomfortable with the director's attitude, Miki goes to the museum again late at night, where he sees—.
(Source: Comic Days, translated)