One day, Seiji receives an odd request from Kounosuke to look into the background of a seaweed wholesaler named Hansuke that he is on good terms with. Stylish and dashing, Hansuke is a ladies man who has a talent for business despite his age and his seaweed wholesale shop has been very successful, but Kounosuke is suspicious of his unusual generosity towards him believing that Hansuke has ulterior motives. Seiji is unable to find out anything unusual about Hansuke, but while out on a boating trip he notices that Hansuke has an odd reaction to the kiseru that Goi inhabits. What kind of past connection do Goi and Hansuke have?