キミ犯人じゃないよね？ (2008)

Morita Sakura is a peculiar "freeter" (freelance part-timer) who dreams of becoming a mystery novel writer. While switching between various jobs throughout the series, she also becomes an assistant to Officer Udagawa, a detective who discovers her excellent memory and reasoning skills. On the other hand, Udagawa (who has just joined the police ranks through his father's connections) is fairly inept and has a tendency to fall in love with female suspects. --Tokyograph