Nobuto Matori, a 20-year-old member of his father Yoshitatsu Matori's yakuza-affiliated semi-gangster group, poses as Reika Tosu's boyfriend. His true goal involves targeting her family's inheritance, specifically planning to extort money from her grandparents before killing Reika. His name reflects his nature: "Nobuto" meaning "prolong, stretch" and "person," and "Matori" combining "hemp, flax" and "take, fetch."

He possesses a volatile temperament marked by male-dominated attitudes and a pattern of violence against women. This includes assaulting and murdering at least two former girlfriends, actions he dismisses as accidents. His abuse extends to Reika, leaving visible injuries that alarm her family.

His father Yoshitatsu shields him using yakuza connections, enabling his crimes. This protection stems from Yoshitatsu's intense, though poorly expressed, paternal love formed after Nobuto's birth.

Tetsuo Tosu, Reika's father, discovers Nobuto's threats and murders him during a confrontation in Reika's apartment. After overhearing Nobuto detail his plans to exploit and kill Reika, Tetsuo beats him to death with a rice cooker. Tetsuo and Kasen Tosu then dismember Nobuto's body and conceal it within a garden pot. These remains become a persistent element fueling the subsequent conflict between the Tosu family and the yakuza syndicate.

Nobuto's actions and disappearance trigger the entire storyline. His status as the heir to a yakuza branch intensifies the syndicate's investigation, placing relentless pressure on the Tosu family as they deal with the consequences of his death. His absence continues to drive character motivations, particularly his father's vengeful pursuit of the truth.