Japan's former State Minister of Justice Kakizawa Mito has pleaded guilty to vote-buying charges stemming from a mayoral election in Tokyo last April.

The multiple charges are related to Koto Ward's mayoral election, in which Kakizawa supported candidate Kimura Yayoi.

Kakizawa was accused of ordering his aides to offer a total of about 2.8 million yen, or more than 18,000 dollars, to 10 people including ward assembly members.

He also allegedly instructed the campaign staff of the candidate to run paid online ads, in violation of the law.

Following his indictment, Kakizawa stepped down as a lawmaker on February 1.

In the opening hearing at the Tokyo District Court on Wednesday, Kakizawa said his actions affected many people and caused them great pain. He offered an apology and acknowledged that he bears heavy responsibility. He said he will not contest any of the charges.

Prosecutors told the court that Kakizawa led an election campaign for Kimura to defeat a longtime political rival in his constituency.

Kimura won the vote, but resigned as mayor months later after the scandal surfaced.

The court will rule on the case on March 14.