Senior vice education minister Yoshiaki Harada resigned from his post Thursday for falsely claiming that he was a graduate of the Fletcher School of Tufts University in Boston.
A secretary to Harada said the lawmaker had recently discovered that, contrary to his belief, he had not earned the sufficient number of credits to graduate in 1968.
The 59-year-old House of Representatives member did not make these claims in official election bulletins when he ran for a Diet seat in past elections, according to the secretary.
The former trade ministry bureaucrat is now serving his fourth Diet term.
Chief Cabinet Secretary Hiroyuki Hosoda said Harada's resignation from his post at the Education, Culture, Sports, Science and Technology Ministry was "inevitable" because his intention to do so was strong.
Shinya Ono, a Lower House member representing the Ehime No. 3 constituency, was appointed to succeed Harada.
Lower House member Junichiro Koga was forced to leave the Democratic Party of Japan in January due to his false claim that he had graduated from Pepperdine University in California.
He is now serving as an independent.
Koga's case drew much media attention because he won a Diet seat by beating heavyweight politician Taku Yamasaki, former vice president of the Liberal Democratic Party, in November's general election.