So here's what i found:
1. http://m.koreatimes.co.kr/pages/article.amp.asp? - hb's parents were teacher
idk if it fits the scenario that his mom is a sculptor or it's just her hobby
11:42 "among my relatives have a lot of capable persons. 1 brother graduated from SNU and one is inspector" idk if it's translated accurately (the brother mentioned either his cousin bcs he said "relatives" or real brother?).
4. https://ko.m.wikipedia.org/wiki/현빈 In korean wiki "서울특별시 송파구 잠실동에서 2남 중 막내로 태어났다. 2살 연상인 형은 대한민국 국군 장교 출신인 것으로 알려졌다." which translated as "he was born in Jamsil-dong, Songpa-gu, Seoul, the youngest of two sons. His 2-year-old brother is said to have been an officer of the South Korean Armed Forces"
Link reference: http://m.hankooki.com/m_sp_view.php?WM=sp&FILE_NO=c3AyMDExMDExMzA3NDc1Nzk2MDEwLmh0bQ==&ref=ko.m.wikipedia.org&isNv=
(When actor Hyun-bin decided to enlist in the Marine Corps, he believed he had received good advice from his brother, who was an officer. Hyun-bin had many conversations with his family before receiving the application. His brother, Tul, who was an officer in Locke, encouraged the Marinecorps to support him and bought Hyun-bin's will. Hyun-bin's company said, "I grew up in a very straight family and have a positive idea about military service. I understand that he first decided to join the Marinecorps and then consulted with his family." Hyun-bin was interviewed at suwon county office on December 24 last year. A decision will be announced in early February. This official said, "If there is no case, it seems to go to the Marine Corps and go to the MarineCorps. The enlistment period will be in March.")
That's all the info i could obtain with almost zero korean and help of google translate.
Also keep in mind that he was born in jamsil and went to school in gangnam. He must be from middle upper class household.