Hayashi Niko (Ohgo Suzuka) is a mature middle school student with heightened hearing and the ability to mimic the voice of anyone she encounters. Sudo Ichiro (Matsuyama Kenichi) is an immature Otaku who is obsessed with toy robots. Together they will form Sexy Voice and Robo; a spy team that solves various cases.

Cast
* Matsuyama Kenichi as Sudo Ichiro (Robo)
* Ohgo Suzuka as Hayashi Niko
* Murakawa Eri as Hayashi Kazumi
* Okada Yoshinori as Nanashi Hideyoshi
* Asaoka Ruriko as Makyouna Maki
* Tsukamoto Shinya as Hayashi Takeo
* Katagiri Hairi as Hayashi Yukie

Guests
* Nakamura Shido as Mikabozu (ep1, 11)
* Rokkaku Seiji (ep1,2,9)
* Murakami Jun as Goto (ep2)
* Kashii Yu (ep3)
* Ichikawa Miwako (ep4)
* Hankai Kazuaki (ep4)
* Kurokawa Tomoka (ep5)
* Iriyama Noriko (ep5)
* Naka Riisa (ep5)
* Horan Chiaki (ep 5)
* Takase Yukina (ep5)
* Kinami Haruka (ep5)
* Ryo (ep6)
* Shiraishi Kayoko (ep6)
* Ogi Shigemitsu (ep6)
* Moro Morooka (ep7)
* Takahashi Issei (ep7)
* Kobayashi Satomi (eps 8-9)
* Motai Masako (eps 8-9)
* Tomosaka Rie (eps 8-9)
* Mike Maki (ep9)
* Sasai Eisuke (ep10)