Let's take a closer look now at the scandal which may take Shinzo Abe down.

The allegations center around the 2016 sale of state-owned land to Moritomo Gakuen, a private school operator. The sale was clinched at a price well below market value, but it was also claimed that Abe's wife, Akie, who supported the school's ultra-nationalistic education policy, helped push the deal through. Akie Abe was initially named honorary principal of an elementary school which was planned to be built on the site, but she withdrew after the scandal came to light early last year.

On Monday, the finance ministry admitted that it had doctored official documents relating to the land sale before they were sent to MPs. Prosecutors say they found 14 instances of such alterations. The prime minister now says he's keen to bring clarity to the episode.

SHINZO ABE JAPANESE PRIME MINISTER "This is a situation that has shaken up the trust of the entire government. And as head, I feel responsible. I would like to deeply apologise to all citizens. In order to find out why this happened and make everything clear, we will continue our investigation."

Abe denies he or his wife did any favours for the school operator, and has even offered to resign if evidence to the contrary is provided.

Meanwhile, calls for the prime minister's resignation grow louder, with hundreds protesting outside his Toyko office on Monday evening.