Seulgi hanya seorang siswi biasa di Seoul High School, bahkan terlalu biasa untuk bisa diajak Oh Sehun si Kingka sekolah menjadi pasangan dalam acara prom sekolah mereka. Lalu bagaimana dengan Jongin, sahabat sekaligus cinta pertama Seulgi? Akankah Jongin mengajak Seulgi ke prom seperti tahun lalu?

I used to be so happyBut without you here I feel so lowI watched you as you left but I can never seem to let you go'Cause once upon a time you were my everythingIt's clear to see that time hasn't changed a thingIt's buried deep inside me but I feel there's something you should know Zara Larsson - Never Forget You

Krystal -- Sunggyu -- Myungsoo