Antique appraiser Nishitsu Hogen is stabbed to death with a spear. At the crime scene are securities company employee Tojima Motoyuki, former real estate company president Chono Kinji, and art museum director Sakamaki Suzue, all of whom came to have their black lacquer trays appraised. Professor Agasa recalls what happened when Nishitsu was still alive... Meanwhile, Sera is curious about one of Okiya's behaviors.