S1, E2: Mornings are chaos for the Seo siblings: Yong Xin struggles with her wild curls while Yong Yi, annoyingly flawless, nags her to hurry. At school, delinquent heartthrob Du Yaxiu’s sudden return causes a stir—Yong Xin assumes he’s here for her, unaware he’s actually hunting the mysterious note-writer (her). Too late, she realizes her coded letters are missing.