Yoshiyuki Kojima (小島 良由起, Kojima Yoshiyuki) known in online circles as "Dragonfly", is an ego-driven custom persocom-builder.
Unlike Minoru, he is obsessed with persocoms and even kidnaps Chi during the course of the story.
He attempts to hack into Chi, using all of his persocoms in a massive, parallel, processing network. (With the exception of Kotoko, who he built previous to the start of the series).
During this time, he makes an attempt to inappropriately touch Chi. Freya takes over, restraining him with the cords he had plugged into her ears. She then attacks him with a concussion blast, blowing out the windows in his house and knocking him unconscious.
Afterwards, he is seen assisting Minoru to help solve the mystery of Chi and the Chobits.
In the manga, he appears two more times in Vol.6; during which he mentions that Chi "is too interesting a safe not to try and crack!"