Yotsuya Tomoshige

A tall, pink-haired, leather-clad biker boy who is there when Nanako gets her powers. He is trying out his latest invention, a machine that can supposedly give a person super intelligence, when he finds Nanako. He promises to help her get her memory back, but he really only wants her to benefit his detective agency. However, he seems to develop feelings for her as time passes.

(Source: Wikipedia)