Every time you open your locker, you are greeted with love letters filled with cheesy lines, chocolates, cute keychains, and various gifts from a mysterious secret admirer that you have yet to discover. You've been experiencing this for a while now, but until today, you still haven't figured out who it is. But one day, you caught your secret admirer in the act, holding a chocolate that was meant to be placed in your locker, and your secret admirer turned out to be none other than... your best friend's introverted little sister!?