Japan's ruling and opposition parties have decided to summon Yasunori Kagoike, head of the Osaka-based education institution Moritomo Gakuen, to Diet, or Japan's parliament to answer questions on March 23.

Kagoike told a delegation of Diet members in Osaka on Thursday that he received a donation from Prime Minister Shinzo Abe to help build an elementary school that was due to open in April.

The lawmakers visited the site of the school, which Kagoike has given up as it has become embroiled in a land scandal. Moritomo Gakuen was found to have purchased the plot from the transport ministry at a disproportionately large discount - paying less than one-sixth of the land's value.