Season 1, Episode 10

Yijeong unexpectly sees Gaeul on the street and helps to revenge her bad boyfriend. Jandi clears up her misunderstanding about Junpyo, and the two go out on a date on Valentine's Day. They bump into Junpyo's mother, and Junpyo tells her not to do anything bad to Jandi. The mother, who doesn't even think of F4 as the friends of Junpyo, starts her next action to cut Jandi off from Junpyo as she thinks Jandi is ridiculously improper to her son.