"Uncles, take my deep bow", said Seo Soon-gyo (55), as her 87-year-old father, Seo Jin-ho, met with two younger brothers, Chan Ho and Won Ho.
Almost 20,000 people have participated in 20 rounds of face-to-face reunions held between the countries since 2000.
Most of the participants in the reunions are in their 70s or older and are eager to see their loved ones once more before they die.
Some of those selected for this year's reunions gave up after learning that their parents or siblings had died and that they could only meet more distant relatives whom they had never seen before.
Ninety-three families from both sides of the border were initially set to meet this time around but four South Korean members canceled at the last minute because of poor health, the Red Cross said.
South Korean President Moon, himself a member of a separated family from the North's eastern port city of Hungnam, said on Monday that the reunions should be sharply scaled up and held on a regular basis and include exchanges of visits and letters.
"He is very old so I really want to express my gratitude for being alive for a long time". North Korean leader Kim Jon Un and South Korean President Moon Jae-in agreed in April to resume holding the family visits, as part of efforts to improve diplomatic relations.
"Oh brother, it will be great when reunification happens", she said.
Many of the North Korean women wore traditional dresses, known as hanbok in South Korea and joseon-ot in the North, and all wore the ubiquitous pins commemorating North Korea's founder Kim Il-sung or his son and successor Kim Jong-il, while the Southerners wore their best suits.
South Koreans head for family reunions in North after decades apart
Her son showed her pictures of his family in the North - including her late husband - telling her: "This is a photo of father". The two Koreas have held 20 rounds of face-to-face family reunions since the first-ever inter-Korean summit in 2000.
South Korean Lee Geum-Sum, 92 (left) meets with her North Korean son Lee Sung-Chul, 71, during a separated family reunion meeting Monday at the Mount Kumgang resort in Mount Kumgang, North Korea.
But the reunions are often also tinged with frustration, with many North Koreans determined to publicly demonstrate their allegiance to the regime, out of genuine loyalty or just fear.
Baik, who will meet his daughter-in-law and granddaughter, said he had packed clothes, underwear, 30 pairs of shoes, toothbrush and toothpaste as gifts. "In fact, meeting them for that little moment made me miss them more ardently than before", she said in an interview.
Thousands of families have been divided after the 1950-53 Korean War, which ended in a cease-fire, not a peace treaty, leaving the Korean Peninsula still in a technical state of war.
"Expanding and accelerating family reunions is a top priority among humanitarian projects to be carried out by the two Koreas".
North Korea has shifted to diplomacy in recent months. "Oh, I should ask him what his father told him about me".
Starting on Thursday, there will be a meeting of another 88 groups of relatives, 469 from the South and 128 from the North, according to Seoul's Unification Ministry. War refugee parents were finally able to see their own children for the first time after more than six decades. "As a member of a divided family myself, I sympathize deeply with that sadness and pain".
More than 57,000 South Korean survivors have registered for the family reunions, which usually end in painful farewells.
North Korea is reluctant to accept calls for more reunions.