Seo Hyun-jin: I'm an "early" 1985-liner, but I get along comfortably with both 1984 and 1985-liners.

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Jang Do-yeon: Friends born in '85, friends born in '84... How did you handle it? How did you sort out the hierarchy?
Seo Hyun-jin: Since we are all just friends, everyone else is either older brother/younger brother or older sister/younger sister, but I don't really care. Yeah, my philosophy is just to avoid meeting people when the social hierarchy gets all tangled up (it's a bit embarrassing).
Jang Do-yeon: Then, among the 1984-liners, who is the one you consider a friend?
Seo Hyun-jin: I'm friends with Jun-hyuk (born '84), and Yeon-seok oppa is probably also '84. But they told me to call him "oppa" there. They said they don't act like friends with '85-liners, so they told me to just call him "oppa." So I coolly go, "Oppa!" But wait, am I allowed to hit him if he's "oppa"?
Jang Do-yeon: Then what about the 1985-liners?
Seo Hyun-jin: Everyone born in '85 is a friend. When I first met Lee Kwang-soo, we were the same age, so I was so happy. We were like elementary school kids holding hands while filming the historical drama. I remember wandering around together like we were at a folk village, haha.