Rozan Shinoyama leads the Shinoyama Clan and its powerful Financial Group, overseeing diverse interests like banking, security, and medical tech. He presents a relaxed, grandfatherly demeanor focused on family enjoyment in retirement. Yet beneath this affable exterior lies a formidable individual possessing an iron will, sharp insight, and the capacity to intimidate threats. He openly acknowledges he is not a "good person," considering those who think so poor judges of character, often masking sympathy with self-interest. During overseas travels, Rozan encountered and married Kanon, a woman suffering from amnesia with no past recollection, despite family objections over their age difference. They had a son, Polka Shinoyama. Rozan secretly learned of Kanon's traumatic past, including her anguish over a lost child named Riz, through her troubled sleep. He also intervened decisively in Xiaoyu Lei's life, rescuing the crippled boy from human experimentation. Rozan purchased Xiaoyu, provided him with advanced cybernetic limbs, and employed him as a bodyguard. At a family gathering, Rozan maintained a genial atmosphere but swiftly silenced his son Gorō's business inquiries with a threatening glare, asserting his retired status. He confronted "Polka" (the reincarnated Corpse God possessing his son's body) about running away, correcting the apology to "I'm home" and patting his head. However, in private, Rozan immediately discerned the impostor despite identical appearance, voice, and mannerisms. He drew his katana, demanding the truth about his son while expressing unwavering parental recognition even near death. After the Corpse God and Misaki Sakimiya saved Rozan's grandchildren Kazuki and Shizuki from assassination during an estate arson, Rozan bowed in gratitude. He accepted the Corpse God's explanation of otherworldly reincarnation after witnessing proof like summoned eyeballs. While initially threatening Misaki for murdering Polka, he stayed his hand upon encountering Polka's soul within a shark plushie and negotiated a solution. Rozan proposed transferring the Corpse God's soul into a company-developed humanoid robot, facilitating Polka's return to his body. He expressed concern that a family member orchestrated the hit on Polka, viewing it as possible karmic retribution, and later arranged for Sayo Shinoyama and Xiaoyu Lei to stay with the Corpse God. Rozan is the father of Gaku Shinoyama (from his first wife) and Polka Shinoyama (with Kanon), and grandfather to Takeru, Kiri, Suzuka (deceased), Sayo, Kazuki, and Shizuki. His interactions reveal genuine care; he enjoys shark movies recommended by Sayo and prioritized protecting his grandchildren over immediate answers about Polka's fate. Learning that Riz (the Corpse God's original identity) was Kanon's child and thus Polka's half-brother led Rozan to regard Riz as his own son. His given name Rozan means "calculus." His surname Shinoyama combines "four" (四, shi), "from" (乃, no), and "mountain" (山, yama).