YunJae is the couple's name for U-Know Yunho and Hero Jaejoong, both members (er, sort-of former member in Jaejoong's case) of Korean boy-band TVXQ. Note that they are not officially a couple - a relationship between them is purely fan speculation.
No. It's a Korean gay couple name. The collaborates of two people's names. Yunho and Jaejoong. Oh, and they're in one drama. It's called Banjun drama.
LOL YUNJAE! haha are you a shiper? XD anywayy~ no they're not dating. ^^;; though a lot believe and want them to :) haha its kinda cute ^^ keke. theyre just a coupling for fan service and yee ^^;; >.<
The fanfic you're referring to is likely titled "The Wedding" by the author mrsjaejoong. In this story, Jaejoong moves away, and Yunho, who cheats and marries someone else, later faces complications when Jaejoong returns and discovers Yunho's wife is unfaithful. The narrative explores themes of love, betrayal, and the complexity of relationships.