Kengo Satake, the boy’s 48-year-old father, told police that he “argued with his son for not studying” before a test to enter a private junior high school, according to public broadcaster NHK.
AFP reported that the son, named Ryota, died from loss of blood in hospital on Sunday, as confirmed by officers working in Aichi prefecture in the city of Nagoya.
The father was arrested after hospital staff phoned the police. He told the officers that he had stabbed Ryota “by mistake”.
NHK said that the boy was hoping to gain a place at one of the leading private schools in Aichi prefecture and his father had regularly scolded him over his studies.
Local media reported that the boy’s mother was at work when the incident occurred.