The Kyoto File (1) - S1.E10

A serial killer taking a lock of hair from each victim leads Hisoka and Tsuzuki to Kyoto, Watari's home town. When a lock of the murderer's hair is found at the scene of the latest victim, the pair discover that their criminal is none other than Dr Muraki and a run in with the evil doctor leaves Tsuzuki battling with memories of his past. However Muraki knows more about Tsuzuki's past than he is letting on, and what Tsuzki doesn't know could just be his downfall.