Do we like Shinjiro Koizumi?
Our score: 6 out of 10. No harmful words about people turned up, but his Yasukuni visits, one campaign apology and a thin record on LGBTQ+ issues keep him mid-table.
Koizumi is the son of a popular former prime minister and studied at Columbia University. He got his first cabinet post, environment minister, in 2019 at 38. Back then Western commentators were already tipping him as a future PM, and these days he's Japan's defence minister.
His environment stint was memorable for the wrong reasons at first. He said climate action had to be “gotta be fun, gotta be cool, gotta be sexy, too”, and joked about wanting a steak every day, which went down badly given cattle's link to warming. Activists called him an unknown quantity. Yet at his first press conference he said of nuclear power “I would like to study how we will scrap them, not how to retain them”, which was a brave line in a party that backs restarts.
His messiest personal stoush came in September 2025 during the party leadership race. The weekly Shukan Bunshun reported that an aide pressed campaign supporters to post praise of him online, including digs at his rival Sanae Takaichi. Koizumi said he hadn't known about it, apologised, and said some of the comments “went too far and were inappropriate”. That's a campaign-team embarrassment, not a pattern of nastiness, though it did cost him a bad news cycle.
He was also on the receiving end later. Shukan Bunshun reported allegations that supporters of Takaichi made online videos calling him “incapable” and a puppet of hereditary politics. Takaichi denied the reports in Parliament, saying her office told her no such videos were made, and she later made him defence minister. Abuse aimed at him doesn't count against him either way.
On the harm check, nothing turned up in his own words attacking LGBTQ+ people, women, migrants or the planet. The contested thing is Yasukuni: he prayed at the shrine, which honours war dead including convicted war criminals, on 15 August 2026. He said he was offering condolences and reaffirming Japan's path as a peaceful nation, but China called it strongly condemnable and South Korea voiced deep regret. Whether you read it as respect for the fallen or a signal about history is where you'll land. Gap: I couldn't open a firm quote from him on same-sex marriage.
As defence minister he's pushing a bigger, more outward-looking military. At the Shangri-La forum in May 2026 he rejected Beijing's charge of “new militarism”, asking “Isn't it strange?” given China's nuclear arsenal, and said Japan wants a region that can stand against coercion. Defence policy is contested, and the reader can decide whether that reads as deterrence or escalation.