The 60-year-old principal of a high school in Niihama, Ehime Prefecture, was found hanged Monday, authorities said.
The incident is the second known case of a principal committing suicide over the widespread problem of high schools not providing sufficient education curricula.
Hiroshi Masaoka, principal of Niihama Nishi High School, was found hanged at his home in Masaki at around 7:30 a.m., police said.
The Ehime prefectural board of education said he left a note in his office in the school that read, "I hope you would give us an instruction so that the students' burden would be alleviated. That is my responsibility from the lack of recognition and decisiveness."
A 58-year-old principal in Ibaraki Prefecture was found hanged a week ago.
He left a note saying he hoped that by sacrificing his life measures would be taken to avoid problems for students due to the insufficient curricula.
A huge number of schools have recently been found to have evaded curriculum requirements to focus on preparing students for more specific university entrance exams.