MPD Transportation Department (Part Four) After remembering that Japan’s signage system is based from England’s, Conan concludes that Kengo Aono is the serial murderer. Touko and Shiori’s dying message was in fact the “no parking” sign. Blue in Japanese is “ao”, and no parking signs are a “no” layered on top of a blue sign. When combined, they form “Aono.” The “7751” on Shiori’s phone meant law article 71, section 5-5, prohibiting any persons using or looking at their mobile devices whilst operating a vehicle. Kengo is the only suspect out of the three who broke such laws. Conan also deciphers Naeko’s message, indicating she’s being held at a planetarium. As true to Conan’s deduction, Kengo unmasks himself and reveals that Aiko, the woman her killed herself, was his girlfriend. Touko and Shiori pulled him over, thereby stopping him from saving Aiko. Aiko left a message for Kengo before she died, causing him to break down in tears. Chiba accidentally sets Kengo’s trap but is saved by Naeko, who he recognizes as his childhood friend. Kengo is arrested for the murders.