Older brother of Kuronuma Aoba, does not like his younger brother at all. Aoba had always acted all smart and appeared highly aware of other people's needs, which somehow never failed to stir a weird kind of annoyance in Ran. Ran was Blue Square leader during conflict with Yellow Scarves, that happened one year ago. After that he starts working for Orihara Izaya. Izaya gave him information about Masaomi's girlfriend Saki and later on Blue Square members under Ran's command would kidnap her to lure Masaomi out. But Kadota and his gang would save Saki defecting from Blue Square. Ran and other top members were arrested by police after Saki stated about her kidnapping.