The Death Mansion and the Red Wall (Item on Hand) Yamato tells Koumei to take Ran and Conan with him to investigate the four suspects. They learn that Akashi and Aoi were avid chess fan and that Aoi was adored by all her friends. After investigating the four, they believe Naiko is involved in the murder in some way and travel to his apartment to arrest him. Upon arrival, they find that Naiko has been strangled and that the culprit had spray painted the wall in front of Naiko red. Koumei then heads off to investigate the case on his own.