As Eun-jae and Ye-eun try to cope with the stresses of a new semester, Ji-won is still her usual perky self, but something keeps troubling her.

As Jo Eun struggles to define her friendship with Ye-ji, Eun-jae frantically searches for a way to undo the message she sent to Jong-yeol by accident.

Suspecting Kwon Ho-chang to be the sender of the unpleasant text message, Ye-eun enlists Ji-won's help in figuring out what kind of person he is.

All the pieces of Ji-won's childhood memory finally come together. Meanwhile, Jin-myung stresses over keeping the "promise" she made to Heimdal.