That unexpected moment took place at the end of the summit on January 13, in Nara, Japan - the homeland of Prime Minister Takaichi.
In front of the camera, the two leaders improvise with the song Golden in Netflix's K-Pop series Demon Hunters and BTS's global hit Dynamite.
If Ms. Takaichi showed the maturity of a drummer who used to play in a heavy metal band in college, then Mr. Lee Jae Myung surprised in a different way.
The President only learns to play drums for 5 or 10 minutes" - Ms. Takaichi said in a video posted on the Prime Minister's Office's YouTube channel.
And South Korean President Lee Jae Myung, with a rare sarcasm in a head of state, wrote on social media: "Although our rhythms are not completely the same, we have both tried to catch up together. We will build a relationship towards the future with one heart.
That "improvisational performance" was not in vain. It took place just a week after Mr. Lee Jae Myung's visit to Beijing.
From Beijing to Nara, Mr. Lee Jae Myung appeared as a leader trying to balance the discord among major neighbors.
The idea of playing drums was Ms. Takaichi's "surprise gift". She recalled a fleeting saying of Mr. Lee Jae Myung in his first meeting in Gyeongju, when he shared that playing drums is a lifelong dream. After the performance, the two leaders signed and exchanged drumsticks - a detail imbued with symbolism.
Personal gestures began before that. When Mr. Lee Jae Myung just arrived at the accommodation before the conference, Ms. Takaichi suddenly appeared to greet him, bowing 90 degrees - a ritual that shows deep respect, quickly becoming a topic in the Korean media. She also told the President's wife, Ms. Kim Hea Kyung: "I have seen her on television, but in real life she is much more beautiful.
Known as a conservative politician who is tough on security, Ms. Takaichi takes advantage of her love for Korean culture - from grilled seaweed, cosmetics to television dramas - as a soft diplomatic bridge. Meanwhile, Mr. Lee Jae Myung shows a flexible style, willing to use cultural symbols to cool down political differences.
After the "stage" layer, the two sides still achieved specific results: Agreed to conduct DNA tests for victims of the Chosei coal mine in 1942, strengthen cooperation in combating fraud, launch a dialogue on economic security and exchange views on North Korea.
This morning (January 14), the two leaders visited Horyu-ji Pagoda, one of the oldest pagodas in Japan.
