"Running Man" Song Ji Hyo sweated over her graduation picture.

On SBS "I Like Sundays - Running Man," the members dressed up as high school students.

In the opening, Song Ji Hyo made an appearance in a high school uniform brushing her hair. You Jae Suk said, "Ji Hyo used to play a lot in high school, and she got more composed as she god older."

Song Ji Hyo kept saying, "That's not true, don't believe him," and then finally got angry and said to You Jae Suk, "Why are you doing this?"

In addition to the conversation of the two, Song Ji Hyo's high school graduation picture was revealed. On the subtitle it read, "Song Ji Hyo's legendary Chun Sung Im period," making the audience laugh.