When he was a child, Sumio and his friends Fuyuki, Hiseki and Riru Yukimura lived in Mikumo 77. During the Parade riots, Riru is killed and Sumio and his friends are disabled; Sumio's ears were stabbed out, making him deaf. Sumio and his friends form the Mikumo Boys, who vow to get revenge on the Yukimura Group whose actions had caused the riots.
As a young man, Sumio Kodai trained at the Central Police Department. Using lipreading other skills, he cheated on the physical tests and used bribery to skip the hearing tests. He was then assigned to the 2nd Division of the Heinous Crimes Unit, where he used Hiseki's accessibility technology to avoid being found out. His first investigation was "Power Girl" in 1994. During his time at the HC Unit, he formed a close friendship with Tetsugoro Kusabi, one that Tokio Morishima even believes to be romantic or sexual in nature.
In 1999, twenty years after the murder of Riru, the Mikumo Boys put their plan into motion, which decimates the Yukimura Group using illegal activities and results in the suicides of Fuyuki and Hiseki. When Kusabi finds documents revealing Sumio as the ringleader of the Mikumo Boys, he rushes out and arrests him. Shortly after, he is discharged from the HC Unit, resulting in the dissolving of the 2nd Division. Despite this, Kusabi remains close friends with Sumio and frequently visits him in jail. At some stage of his life, Sumio was cloned to create a boy named Sumio Mondo, who himself was cloned numerous times.
The timeline document on the official website mentions that Sumio investigates future cases following the events of Flower, Sun, and Rain, but it is not specified what Sumio it is talking about; it seems possible that Mondo took back the Kodai identity. The fate of the identity of Sumio may be explained in Shirubaa Jiken 25 Ku.
Official website descriptionEdit
|Originally from the industrial city of Mikumo, Sumio was assigned to the Heinous Crimes Unit after graduating from the Central Police Academy. Since then he has served effectively as the backbone of the 24 Wards Police Department. He has a partnership with Kusabi and always likes to get into the heart of an investigation. He has a serious attitude and is above petty disagreements within the department over status and promotion, focusing only on preventing crimes and solving mysteries. His history suggests that he gave up the chance to make a bigger name for himself out of choice, though his real motives remain unclear.|