This compilation image shows Kim Hye-kyung (L), the wife of Democratic Party presidential candidate Lee Jae-myung, and Kim Keon-hee, the wife of People Power Party presidential candidate Yoon Suk-yeol. (Yonhap)

The wives of the two leading presidential candidates emerged as a key variable in this year's election as both were hit with embarrassing scandals that negatively impacted their husbands' campaigns.

Kim Hye-kyung, the wife of ruling Democratic Party candidate Lee Jae-myung, was often seen accompanying her husband on the campaign trail before a major scandal broke over the Lunar New Year holiday from late January to early February.

The scandal centered on allegations that an aide to Kim bullied a lower-level public servant at the Gyeonggi provincial government into running various personal errands for her when her husband was governor.

The public servant was allegedly ordered to pick up drug prescriptions on Kim's behalf and leave them at her door, fetch packs of beef and sushi and deliver them to the governor's wife, and sometimes use a credit card belonging to the provincial government to make Kim's personal purchases.

Lee cast the issue as a problem among his staff, saying he failed to properly supervise them and believed there was a "procedural" problem in their use of the government card.

The scandal eventually forced Kim to hold a press conference and apologize to the nation.

Born in 1966, Kim majored in piano at Sookmyung Women's University and was introduced to Lee in 1990 as she was preparing to move overseas to further her studies.

The couple were married within six months and Kim became a full-time housewife. The couple has two sons, born in 1992 and 1993, respectively.

Lee, who was born into a poor family and worked in a factory as a boy, has recalled that the first time he set foot in an apartment was when he visited his wife's family.

Kim's elder brother had studied at Stanford University and Lee was introduced to a "completely different world from the world I had lived in."

Lee has also described their meeting as an encounter between a young man who had never laid a finger on a piano and the daughter of a family that owned a piano.

Unlike Lee's wife, Kim Keon-hee, the spouse of candidate Yoon Suk-yeol of the main opposition People Power Party, never joined her husband on the campaign trail.

The two women share the same surname but are not related.

Kim Keon-hee was accused of accepting bribes and manipulating stocks long before Yoon launched his presidential bid.

She also faced constant rumors about her alleged association with shamans and was even believed to have worked in shady nightlife establishments.

Once the campaign got under way, however, the biggest blow came in the form of allegations that she lied on her resume when applying for jobs.

Kim, who is now president of a cultural contents company, was accused of exaggerating her credentials on the applications she sent to two universities in 2007 and 2013.

The attacks culminated in a press conference where Kim apologized and sought the nation's forgiveness.

Born in 1972, Kim majored in painting at Kyonggi University and later earned master's and doctoral degrees in art education and digital contents design, respectively.

She worked as an art or design instructor at schools and universities and took part in hosting various art exhibitions, including those of big names such as Andy Warhol, Marc Chagall and Mark Roscoe.

Kim has said she began dating her husband, 12 years her senior, with the help of a Buddhist monk and the two married in 2012.

The couple has no children but has four dogs and three cats. (Yonhap)