Souichirou Kurebayashi

Souichirou Kurebayashi is the deceased brother of the main character, Teru Kurebayashi. Little is known about him other than he was a very talented computer engineer and led a team of engineers that included Tasuku Kurosaki and Riko Onizuka, he supposedly made some software that would sell for a very high price before his death which mysteriously disappeared, this has brought suspicion on the phone he left his little sister, many believing the software was left to her as a sort of uninformed inheritance. He shoved the role of DAISY onto his friend Kurosaki and potentially convinced him using some form of guilt as Kurosaki has openly admitted that he was in some way responsible for Souichirou's death though the contribution is unclear. It was thought that Souichirou was the one who named DAISY after his sisters favorite flower, the blue daisy, however DAISY has admitted to taking on the name after discovering it was the name of a deadly bomb. It is Kurosaki’s codename that he used to hack into illegal government services. Even though Kurosaki stopped hacking, DAISY is still known to be a "genius hacker", thus causing many troubles for Teru when a "fake DAISY" appears.

(Source: Wikipedia)