- This article contains major plot spoilers from the manga that have not been revealed in the anime. Proceed at your own risk.
|Alias||09 (Zero Nine (ゼロキュー Zero Kyū ))|
|Height||161 cm / 5'3"|
|Eye Color||Light Green|
|Date of Birth||April 2nd, 1997|
|Other Relations||Nanako Tenjo (Friend/Ally/Love interest)|
|Manga Debut||Line 6; Monster|
|Anime Debut||Episode 6; Dogmatic|
|Japanese VA||Shouta Aoi|
|English VA||Nathan Wilson|
Kenichi Yoshii (吉井 健一 Yoshii Ken'ichi ) was a member of the CCC in which he went under the code name 09 (Zero Nine (ゼロキュー Zero Kyū )). Unlike Nanako Tenjo (Zero Seven), he worked in the background developing technologies they could use in the field.
He has a genuine crush on Zero Seven, but he initially didn't have the courage to straightforwardly approach her and would often secretly take pictures of her sleeping and collect them.
During Plan B (The Ikebukuro Incident), he learned that there was an inside plan to have Nanako eliminated, so he left the CCC with her in order to protect her. He also decided to put his unhealthy habit of taking pictures of her behind, and become her real friend.
Kenichi is a teenager who is below average build and height for his age. He has short ear-length, beige-colored hair which is styled into a style that resembles a bowl cut. His bangs cover his forehead and frame his face. He wears rectangular glasses which he wears over his light-green colored eyes.
After the timeskip, he seems to have developed a more mature face, and a taller and slightly more muscular build. He also grew his hair out, to about shoulder-length. His bangs also grew longer and frame his face more than before.
- He is the youngest member of the CCC, being only 16 years old.
- Kenichi developed the thermography scope Zero Seven used, as well as a GPS tracking system used to track CCC members.