TV-Series
Description
Kenichi Yoshii, also known by his code number 09 or Zero Nine, is a supporting character who serves as a developer and engineer. He is a young human, initially sixteen years old and later turning seventeen, with a below-average build and height for his age, standing at 161 centimeters. He has short, ear-length beige hair styled like a bowl cut and wears rectangular glasses over his light green eyes. As he matures, his face becomes more defined, he grows slightly taller and more muscular, and his hair lengthens to about shoulder length. He is an orphan, as his parents died in an accident when he was young, leading him to be raised by an aunt and uncle.

Kenichi is a withdrawn and shy individual with a high degree of intelligence, possessing outstanding abilities as a hacker and engineer. He much prefers to work in the background and handle situations from the shadows rather than take a direct or confrontational role. Compared to his partner, Nanako Tenjo, he is described as meek, more kind-hearted, and able to sympathize with others easily. His motivations for joining the CCC did not stem from a hatred of devils, but rather from a deep admiration for Kirio Kikuhara, who recognized his talent and gave him a sense of purpose when his own family did not. Despite his shy and kind nature, he initially exhibits a rather sneaky and obsessive habit of secretly taking photographs of Nanako while she sleeps, collecting them for himself.

In his role as a CCC member, Kenichi works in the background developing the technologies that field agents use. He is responsible for creating the thermography scope used by Zero Seven, as well as a GPS tracking system utilized to track other members of the organization. His primary function is that of a hacker and an engineer, making him the youngest member of the CCC at age sixteen. During the incident known as Plan B or the Ikebukuro Incident, Kenichi discovers an internal plan to have Nanako eliminated. In response, he makes the decisive choice to leave the CCC with her in order to ensure her safety.

Kenichi shares significant relationships with two main characters. He has a genuine and long-standing crush on his partner, Nanako Tenjo, also known as Zero Seven. However, for a long time, he lacks the courage to approach her honestly, which is what leads to his habit of taking clandestine photographs. He is deeply loyal and protective of her. As his character develops, he resolves to abandon this unhealthy practice and strives to become her true friend and steadfast ally, vowing to always remain by her side. Although he is certain that Nanako does not see him as a romantic interest and is in love with Kikuhara, Kenichi confesses his feelings and remains supportive of her, patient with whatever choices she makes. His other significant relationship is with Kirio Kikuhara. Kenichi holds a deep admiration for Kikuhara, who showed faith in his hacking skills when he was a social outcast. He feels that Kikuhara gave him a new world, making him a dear and important person. Even after Kikuhara commits bad deeds and their paths diverge, Kenichi expresses a desire to protect and be there for him.

Throughout the story, Kenichi undergoes notable personal development. Initially insecure and unable to approach his feelings directly, he gains self-confidence over time. This growth enables him to stand up for himself and for the people he cares about. He moves from being a withdrawn observer who hides behind his camera to someone more honest and straightforward, unafraid to speak his mind. By leaving the CCC to protect Nanako and deciding to become a true friend to her, he demonstrates that he knows what he wants and is capable of taking action to achieve his goals.
Cast