At age 43, former Environment Minister Shinjiro Koizumi is the youngest of the nine candidates and one of the three front-runners in the Liberal Democratic Party’s Sept. 27 presidential election.

His polished speaking style in front of the television cameras, his sharp criticism of fellow LDP members caught up in a slush funds scandal and his calls for regulatory reform that spares no sacred cows is reminiscent of his father, former Prime Minister Junichiro Koizumi.

“Both men are theatrical and good at appealing to the public. In that sense, Shinjiro is on par with his father, which is why I’m calling the LDP presidential election the second act of the Koizumi theater,” veteran political columnist Kenji Goto said Wednesday.

But while the younger Koizumi’s style and rhetoric echo those of his father — a telegenic figure and outspoken critic of his party who promised that nothing was untouchable when it came to pursuing structural reform — there are key differences between the two men.

For starters, there is the age at which the son decided to gun for the party presidency, which so concerned the father that he publicly encouraged him to wait until he is older.

“Shinjiro is still young. I told him that he should wait until he’s over 50 years old to run, and he’s still in his 40s.

"But he just grinned in response,” the elder Koizumi told reporters last week.

Junichiro Koizumi lost his first election in 1969, a Lower House contest to replace his father, Junya, who had passed away, before winning a seat in the 1972 polls at the age of 30. But he did not run for the LDP presidency until 1995, when he was 53, losing to Ryutaro Hashimoto. He lost a second time in 1998, in an election Keizo Obuchi won.

The third time was the charm for the senior Koizumi. He won the 2001 party's presidential election at age 59 and went on to serve as party president and prime minister until 2006 before retiring from politics in 2009. The younger Koizumi, then age 28, took over his seat in that year’s general election.

As prime minister, Junichiro Koizumi often criticized the ways of the LDP, even as he made structural reform and the privatization of Japan’s postal system his key policy goals — both of which he accomplished. But despite his successes, he was a loner, an oddball in a party that valued conformity.

The elder Koizumi struggled quite a bit until he became prime minister. Within the party, he was considered something of a nerd. He often acted alone and fought alone, Goto said.

Shinjiro Koizumi did not join a faction after assuming office, unlike his father, who belonged to one that went on to be led by the late former Prime Minister Shinzo Abe. That faction was dissolved earlier this year in the wake of the slush funds scandal. Amid the political firestorm, the younger Koizumi heavily criticized the factional system.

However, he is close to former Prime Minister Yoshihide Suga and his allies, who are backing his run for the presidency.

While Koizumi — along with former Defense Minister Shigeru Ishiba and economic security minister Sanae Takaichi — is still one of the favored choices to win the race to lead the ruling party, he has run into trouble recently.

His pledges to call a snap election as soon as possible and deregulate the labor market, should he win the leadership race, drew strong criticisms from his challengers, especially his top rivals, Ishiba and Takaichi.

When Koizumi announced his candidacy on Sept. 6, he said he would review regulations on the dismissal of workers in order to deal with the country's labor shortage and encourage the transfer of personnel to growth industries. He pledged to submit a bill for this next year.

However, he quickly faced a backlash. Critics charged that he would be opening the door for corporations to fire people as they wish. Koizumi was forced to revise his remarks, saying on Sept. 13 that he is not advocating for a deregulation or liberalization of the labor market.

Whether he is willing to fight for his desired domestic reforms as prime minister, like his father did, is unclear.

Goto added that another key difference between the two men is that Junichiro Koizumi knew what he wanted to do in terms of Japan’s foreign relations. In 2002, he negotiated with, and visited, North Korea's then-leader, Kim Jong Il, in Pyongyang — the first Japanese leader to set foot there. A month after his return to Japan, the North returned five Japanese citizens who had been abducted during the 1970s.

The elder Koizumi also strengthened Japan-U.S. cooperation with then-President George W. Bush immediately after the 9/11 terrorist attacks in 2001.

“He was decisive. That's something I see lacking in the younger Koizumi, and therefore, there are concerns about Shinjiro’s diplomatic capabilities,” Goto said.