North Korea and Kim Jong Un: Meet the known key players in the regime

North Korea fired an intercontinental ballistic missile into Japanese waters, a U.S. official confirmed to Fox News on Tuesday. It was the first since Sept. 15 and one of many in 2017 alone.

As the country's missile and nuclear capabilities appear to advance, here's what you need to know about the known key players in the regime. 

Kim Jong Un

In this undated photo provided on Tuesday, Nov. 21, 2017, by the North Korean government, North Korean leader Kim Jong Un visits the the Sungri Motor Complex in Pyeongannam-do, North Korea. The Trump administration is due to announce new sanctions on North Korea on Tuesday, Nov. 21, 2017, after declaring it a state sponsor of terrorism in the latest push to isolate the pariah nation. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. Korean language watermark on image as provided by source reads: "KCNA" which is the abbreviation for Korean Central News Agency. (Korean Central News Agency/Korea News Service via AP)

Kim Jong Un is the current leader of North Korea. He took power after his father, Kim Jong Il, died in 2011.  (The Associated Press)

Kim Jong Un is the current supreme leader of North Korea, rising to power after his father, Kim Jong Il, died in 2011. His mother, Ko Young-hee, was an opera singer who died in 2004.

Overall, little is known about the 33-year-old’s early life. But he studied in Switzerland before returning to North Korea to attend the Kim il-Sung Military University in the mid-2000s, Michael Madden, the director of North Korea Leadership Watch and a visiting scholar at the US-Korea Institute at Johns Hopkins SAIS, told Fox News. The university, which is located in Pyongyang, the country’s capital, is named after Kim Jong Un’s grandfather.

“We don’t know a tremendous amount about him [Kim Jong Un],” said Madden. “But we have enough for a good picture.”

Contrary to popular belief, Madden said the North Korean leader has a “relatively cool-headed personality” which serves as an asset. “He derives more power by being laid back and cool,” as opposed to being reactive, Madden said.

From an early age, Kim's mother positioned her son to be her husband’s potential successor. She pushed for him to attend military school, Madden said, where he was tutored by top North Korean officials in artillery. His schooling positioned him to be a top contender.

As for the leader’s notorious missile program, Madden said the North Korean leader “views the missile program like a sports team.” In other words, a sports team doesn’t win every game, but learns from its losses -- and Kim Jong Un reportedly takes the same view point.

Kim Yo Jong  

Kim Yo Jong_reuters

Kim Yo Jong is Kim Jong Un's sister. She was recently promoted to a top decision-making body.  (Reuters)

Kim Yo Jong is Kim Jong Un’s sister. The 30-year-old has always been a “tomboy” with a “pleasant” personality, Madden said.

Like her brother, she also attended school in Switzerland at a young age, where she was once described as “sheltered” by the school’s principal, according to Madden.

Despite North Korea’s conservative and patriarchal society, Madden thinks that Yo Jong could easily succeed her brother one day.

“Kim Yo Jong has a bigger policy portfolio [than her brother], and is more powerful than we’re giving her credit for,” Madden said.

Indeed, in October, Kim Jong Un promoted his sister to a top decision making body, replacing her aunt as the Workers Party's Politburo. She also serves as one of Kim Jong Un’s “closest aides,” Madden said, and manages her brother’s schedule, his bodyguards and meetings.

As the saying goes, she’s an “iron hand in a velvet glove,” Madden said.

Kim Sul Song

Kim Sul Song is Kim Jong Un’s other sister and Kim Yo Jong’s half sibling.

Sul Song is the only daughter from her father’s “official marriage,” according to Madden. Kim Jong Il was polygamous, but his official wife -- as a result of a matchmaking by Kim Yong Il's father -- was Kim Yong Suk. Kim Yong Suk was Kim Sul Song’s mother.

Sul Song, 43, is a “very powerful woman” who was a part of the regime’s leadership cohort at one time. As of now, however, it’s not clear if she’s been “put on the side or is working behind the scenes,” Madden said.

Sul Song once served as an interpreter and close aide to her father. She reportedly managed his travel logistics until about 2008, Madden said.

Kim Kyong Hui

Also known as Madam Kim, Kim Kyong Hui is Kim Jong Un’s aunt, and the sister of his late father.

Madden described her as a “very powerful woman.” Now in her early 70s with a shaky health record, Kyong Hui once was the director of the country’s flight industry -- a title that “concealed her real power,” Madden said.

Madam Kim served as her brother’s closest aide, and was also in charge of the Worker Party’s international affairs department, according to Madden. She once led talks with Israel in the 1990s when the country approached North Korea about buying its nuclear program to protect itself from Iran, Madden said.   

Madam Kim, who was once married to Jang Song Thaek, Kim Jong Un’s uncle who was executed in 2013 for reportedly planning a military coup, also served as the executor of Kim Jong Il's will after he died.  

Kim Yo Jong, who is reportedly very close to Madam Kim, often calls her now-retired aunt for advice, Madden said.

"People close to her rose in status within the regime," he added.

Kim Jong Chol

Kim Jong Chol, 35, is Kim Jong Un’s half brother. Unlike his relative, Jong Chol does not have an interest in the country’s politics. Instead, according to Madden, he serves as a contributing writer to some of North Korea’s state-run publications.

He’s reportedly interested in music and films and has a well-documented affection for the singer Eric Clapton. He also has health issues, according to Madden, though it’s unclear what exactly they are.

Kim Jong Sik

North Korean leader Kim Jong Un inspects the intermediate-range ballistic missile Pukguksong-2's launch test in this undated photo released by North Korea's Korean Central News Agency (KCNA) May 22, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.      TPX IMAGES OF THE DAY - RC15563BBDC0

Kim Jong Sik is circled in red in this photo. He is the scientist behind many of the country's missile successes.  (Reuters )

Not much is known about Kim Jong Sik, who is thought to be in his 50s and the scientist behind many of North Korea's missile successes.

In a previous interview with Fox News, however, Madden said that Jong Sik was "plucked from obscurity" by Kim Jong Un, first catching the leader's attention after he helped to successfully launch an Unha-3 rocket in 2012. 

Jong Sik "rose to prominence by fixing and identifying mistakes while developing missiles," Madden said in September. 

Madden said Jong Sik holds the title of "deputy director" -- a title that holds more power than some "senior officials." Jong Sik also has some personnel and policy making power. 

"Kim Jong Sik is someone that might end up serving higher in North Korea -- at some point -- based on his trajectory of his career," said Madden.

Ri Sol Ju

North Korean leader Kim Jong-Un and his wife Ri Sol-Ju attend the opening ceremony of the Rungna People's Pleasure Ground on Rungna Islet along the Taedong River in Pyongyang in this July 25, 2012 photograph released by the North's KCNA to Reuters on July 26, 2012.The Rungna People's Pleasure Ground has attractions such as a dolphinarium, a wading pool, a fun fair and a mini golf course, according to KCNA. REUTERS/KCNA (NORTH KOREA - Tags: POLITICS SOCIETY TPX IMAGES OF THE DAY) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS - GM1E87Q0V6X01

Ri Sol Ju, right, is seen with her husband, Kim Jong Un.  (Reuters )

Ri Sol Ju is Kim Jong Un’s wife and serves as the “first lady” of the rogue country.

Sol Ju is not “necessarily a powerful lady, but can influence his [Kim Jong Un’s] opinion and actions,” Madden said, adding that the country is “really positioning her as first lady” though what her role entails exactly is still evolving, he said.

“She softens his image,” Madden said.

Sol Ju's father is a commander in North Korea’s air force, Madden said, and her marriage to Kim Jong Un was the result of a matchmaking process commissioned by his aunt, Madam Kim.

Additionally, Sol Ju was once a cheerleader and singer.

Choe Ryong Hae

Though not related to the Kim family, Choe Ryong Hae, who’s reportedly in his late 60s, was recently promoted to be the director of the country’s organization and guidance department.

The department, according to Madden, is basically a “glorified human resources agency.” It regulates party members and determines where North Korean citizens work.

Additionally, the department spies on the North Korean population, Madden said.

“His status has always been kind of questionable within the Kim family, and he’s had multiple jobs. But he’s mild mannered, and a ‘yes man,’” Madden said.

Ryong Hae's father was a defense minister in the 70s and 80s, Madden said, and was also a member of the same military unit as Kim Jong Il. He reportedly has a good relationship with Madam Kim.

In the 1990s, according to Madden, Ryong Hae disappeared from public view and was accused of corruption for illegally exporting scrap metal to China -- a crime that would have led to his death. But according to Madden, Madam Kim made a “desperate appeal to not kill him.” Ryong Hae was ultimately spared.

Madeline Farber is a Reporter for Fox News. You can follow her on Twitter @MaddieFarberUDK.