During the March 4th installment of JTBC's 'Hyori's Bed & Breakfast 2', the two stars couldn't help but cry after reading a letter left by their guests, forwarded to Lee Hyori, YoonA, and Lee Sang Soon. 

Lee Hyori sat down and silently read the letter given to them by the two sisters who stayed at the star's home. While reading, tears rolled down her face and she tried to hide them. YoonA, who was doing the dishes at the time, asked if Lee Hyori was crying but she continued to hide it and went upstairs to wash up.

Afterward, YoonA read the letter as well and had a similar reaction. Lee Hyori heard this from upstairs and asked if YoonA was crying but she too denied it, and said, "No hahaha. I think I got the cold from you."

Meanwhile, it was revealed earlier by the two sisters (the guests) that they actually have a little brother and wanted to bring him as well but wasn't able to due to him having Down syndrome.