A murderer has been leaving behind women's heads in the park bathroom with styled hair caked in blood. Because of Yako's concern and Akane's understanding of the slaughtered "hair," Yako asks Neuro to solve this mystery. However, as he does not sense a puzzle in this one, he replies that Yako & Akane should solve the mystery by themselves if they want it so much, remarking that it would be a good opportunity for Yako to "evolve." By fusing Akane with Yako, the latter gains beautiful hair with which she can lure the culprit. After learning from Ishigaki & Sasazuka the identity of the current suspect (the owner of a popular Hair Salon with a criminal record name), she goes to confront him by herself as Neuro is investigating the scene of the crime. As he finds her, the hair stylist is mesmerized by Akane and asks Yako to go to his apartment. As they arrive, he accuses her of knowing his true identity and restrains both her and Akane so as to slice her head off and style her head. Before Yako can be harmed, however, Neuro arrives and rescues her as he eats the culprit's mystery with Akane's help. As he leaves the apartment Neuro points out his disappointment at Yako not being able to evolve. (thetvdb.com)