A South Korean protester during a rally to call for the resignation of President Park Geun-hye, who prosecutors say is suspected of influence-peddling and other charges (Jeon Heon-Kyun/European Pressphoto Agency)

SEOUL — South Korea’s president, Park Geun-hye, is fighting for her political life amid a scandal involving Choi Soon-sil, her close friend who has been dubbed “shadow president” for her role as a secret adviser.

Choi, who is the daughter of a controversial religious leader and who has never held an official position, is suspected of having huge influence over the president — some say she had been manipulating her friend — and is accused of using the relationship for her own gain.

Hundreds of thousands of protesters have taken to the streets every weekend for the last month, calling on her to step down.

The prosecutors have indicted Choi and two former aides to Park on charges including extortion, fraud and divulging classified information. Now the prosecution wants to question Park herself, who they say was an accomplice to the crimes.

But Park remains defiant, fending off the prosecution’s requests to talk to her and refusing to resign. Now the opposition is preparing to begin impeachment proceedings — a process that could take months.

Corruption and influence-peddling scandals have been relatively regular occurrences during the course of South Korea’s democratization, but this case has angered people here because of the sheer scale of the allegations.

Choi is said to have influenced South Korea’s public and private affairs, from its foreign relations to the admissions procedures of one of its top universities.

Here are four examples of Choi’s influence that help explain why South Koreans are so angry.

Leaning on big business

The “Choi-gate” scandal began with the revelations surrounding $70 million that Choi raised for two foundations from the big business lobby group representing more than 50 of South Korea’s biggest companies, including Samsung, Hyundai Motor Co. and LG.

The heads of seven big companies, including the powerful Jay Lee of Samsung, were summoned to the prosecutors’ office on a single weekend to be questioned about their one-on-one secret meetings with the president.

The chief executive of Samsung Electronics has also been summoned twice, as the company is accused of paying money directly to Choi as well as to her foundations.

Samsung sent $3 million to a German company, Widec Sports, connected to Choi last year. The payment was made soon after a merger between Samsung C&T and Cheil Industries, Samsung’s construction and textile business, respectively. The merger was a crucial part of the Lee families’ maneuvering to help Jay Lee consolidate his grip on the conglomerate and position himself as heir to his ailing father, who remains technically in charge of the huge group even though he’s been unconscious in a hospital for two years.

Samsung is the dominant economic force in South Korea, owning interests ranging from an amusement park and a baseball team to hospitals and, of course, the electronics giant. It accounts for about one-quarter of South Korea’s exports, so if it is involved in something, it’s big.

Questions about the appointment of former ambassador to Vietnam

Some South Koreans are wondering if Choi played a role in the unusual appointment of Jun Dae-joo, a businessman turned consultant based in Vietnam, who had never held any position in the government but was suddenly appointed South Korea’s ambassador there in 2013.

South Korea had never appointed a private citizen as an ambassador, so the decision raised eyebrows. The Foreign Ministry said at the time that “the appointment was made as part of the ministry’s effort to
bring in fresh talent from outside the ministry.”

But the current South Korean consul in Ho Chi Minh City, Kim Jae-cheon, gave a surprisingly frank on-camera interview about Jun’s appointment on Nov. 14 to local cable network JTBC.

He asked if Jun’s appointment was the result of his relationship with Choi’s family. Jun is believed to have been a longtime adviser and friend to Choi’s nephew, Chang Seung-ho, who runs a high-end kindergarten in Vietnam, local reports say.

According to Kim, the presidential office specifically ordered that Chang be invited to a banquet held for Park when she made an official visit to Vietnam in 2013.

Then, earlier this year, the South Korean Consulate sent a letter to local authorities in Ho Chi Minh City asking them to help Chang’s kindergarten business in the city, Kim said. A Foreign Ministry spokesman said the ministry is looking into Kim’s allegations.

Bending rules in university admissions

But it wasn’t just national or corporate affairs over which Choi apparently wielded influence. In a society where your university’s name and ties are often critical for opening doors, students strive to get a degree and build an alumni network from the top-ranked universities.

However, Choi’s daughter Chung Yoo-ra didn’t need to study hard. She attended only 17 days in her entire third year in high school and was at the very bottom of her class, the Education Ministry says.

She was accepted into the prestigious Ewha Women’s University, even though she did not have the necessary grades. Once at the university, Chung didn’t have to go to classes or submit papers to get grades, and apparently professors intervened in her projects to ensure that she passed her courses, according to the Education Ministry’s investigation findings.

“We definitely feel responsible for [failing to properly] monitor the university,” the education minister said.

The university and faculty, including the former dean of the university, are expected to be investigated by the prosecutors. Prosecutors on Tuesday raided the university’s offices, confiscating computer hard drives, cellphones and documents related to admissions in 2015.

This part of the scandal is particularly galling for many young South Koreans, who feel like they live in “hell” because of the difficulties in getting into the right universities so they can land good jobs with benefits.

The “missing seven hours”

When Park hired a lawyer to deal with the mounting allegations against her, he appealed to the public to respect Park’s privacy “as a woman.”

This plea was initially met with bewilderment, but it soon emerged that Park had been receiving secret treatments at a luxurious private clinic known for its anti-aging treatment and stem-cell research in Gangnam, an upscale area of southern Seoul. Then people cottoned onto the attorney’s request.

The clinic, called Chaum, had been treating Park for free even before she became president, local media reported, citing inside sources.

This situation, too, has been linked to Choi.

Choi had been collecting unspecified injections on Park’s behalf so the president could be treated at her convenience. The doctor who prescribed the medicine has been suspended for violating the law, as it is forbidden to prescribe medicine for someone other than the patient.

As this part of Park’s private life was revealed, it kindled other suspicions related to “the missing seven hours,” as they’re dubbed here.

This refers to the day that the Sewol ferry sank in 2014, claiming more than 300 lives, mostly high school students.

The presidential office says Park was informed of the Sewol incident by phone and other reports. But when she appeared in public to hold an emergency meeting, she asked why the students with life vests could not be rescued. It baffled many that the president might have not known that the ferry had already sunk with the students trapped inside.

It later emerged that no one from the presidential office, including her chief secretary, had seen her between 9:53 a.m., when Park first received a written report about the incident, and 5:15 p.m., when she asked for the emergency meeting to be called.

She was criticized for failing to handle a crisis where every minute counted, and despite public curiosity and speculation, Park has never adequately explained what she was doing during those hours. With the emergence of news about the anti-aging clinic, some South Koreans are now wondering if the president was unconscious or undergoing beauty treatments during this time.