Sexy Voice and Robo

 is a Japanese manga series written and illustrated by Iou Kuroda. It was originally serialized in the "seinen" manga magazine "Spirits Zōkan Ikki" (re-branded as "Monthly Ikki" in 2003) between November 2000 and December 2002, with its chapters compiled in two "tankōbon" volumes. "Sexy Voice and Robo" is currently unfinished. Kuroda has stated that he planned to write a continuation some day.
The series has been licensed for English language release in North America by Viz Media, being released in a single volume in July 2005. 
It was adapted into a 11-episode Japanese television drama, which aired on Nippon TV between April and June 2007.
The manga won the 6th Grand Prize at the 2002 Japan Media Arts Festival.
Plot.
The story is about the adventures of a 14-year-old girl named Nico Hayashi, who uses her talents of changing and altering her voice to manipulate men over the phone who want to participate in enjo kōsai. Through this she learns a lot about human nature, and gains a keen understanding of people through their voices. An aging gangster notices her talents and decides to hire her to solve various cases. While Nico is on her first case, she meets with a geeky man named Iichiro Sudo, who has an obsession with robot toy models. This obsession that leads Nico to call him "Robo", and the two become an unlikely team. After completing her first case Nico proclaims herself "Sexy Voice" and a variety of short loosely linked character-driven adventures ensue.
Media.
Manga.
"Sexy Voice and Robo" is written and illustrated by Iou Kuroda. It was serialized in Shogakukan's "Spirits Zōkan Ikki" (re-branded as "Monthly Ikki" in 2003) from November 30, 2000 to December 25, 2002. Shogakukan published the chapters into two "tankōbon" volumes, released on November 30, 2001 and February 28, 2003. "Sexy Voice and Robo" is currently unfinished. In January 2007, Kuroda stated on his blog that he planned to write a continuation some day. In 2016, Kodansha republished the series with new cover illustrations and two additional stories on March 23 and April 22.
In North America, Viz Media released the series in a single 400-page volume on July 19, 2005.
Drama.
An 11-episode Japanese television drama, starring Kenichi Matsuyama as Robo and Suzuka Ohgo as Nico, was broadcast on Nippon TV from April 10 to June 19, 2007.
Reception.
The manga won the 6th Grand Prize at the 2002 Japan Media Arts Festival.