Sayo Kotobuki

Sayo is the 14-year-old younger sister of Ran. She is completely obsessed with the Odaiba Cop show, often imitating the show's main character Detective Kudou. In the first season she patrols around with Masato Iwai to form the Junior Detectives. Her catch phrase is "datchu" (You bet) which she also got from watching Odaiba cop.

(Source: freewebs, Wikipedia)