Pen to Wappa to Jijitsu-konペンと手錠と事実婚; Pen to Tejou to Jijitsukon; A Pen, Cuffs, & a De Facto Marriage; Pen, Cuffs, & a De Facto Marriage; Hôn thú giữa bút và còng tay

A middle-aged detective, Eiji Kirisame (40), meets a strange high school girl at the scene of a certain crime. She doesn't speak a word, but she helps solve the case using her drawings. However, suddenly this middle-aged detective is getting a marriage proposal from this girl!