Yako Katsuragi  

Slave no.1, The Female High School Detective, The Piggish Detective, 桂木 弥子

(Source Manga) Yako is a 16-year-old high school girl and the very first character introduced in the manga. She meets Neuro when he appears and desecrates her fathers shrine while promising to help solve the mystery of her fathers death. This meeting quickly leads to a partnership Yako becomes Neuros cover, pretending to be an investigator while Neuro acts as her assistant. She has an insatiable appetite (which people often associate her with) -with a cast iron stomach to match-, and a knack for understanding human psychology that occasionally provides Neuro with information he is unable to obtain because he is unfamiliar with how humans operate. Yako is even able to understand Neuro, to a degree, thanks to an amalgamation between the two aforementioned traits; she compares Neuros opinion of food (puzzles) over that for oxygen (shouki) to an experience that she had (hunting for oysters under water). Neuro enjoys abusing her, though he does compliment her at times of success, albeit through a patronizing tone. Despite all that Yako goes through on a daily basis, she is relatively calm during high-stress situations, such as being kidnapped by Sai. While her time with Neuro has definitely been a factor in this, it is left to question if Yako had this trait before she became Neuros front. It is also notable that Yakos abilities, and potential, as an actual detective is shown to be growing over the series, starting with the Aya Asia case, albeit differently between both the anime and the manga.