A Korean birthday tradition brings together the past, present, and future. Hoon's baby sister Binna is about to turn one year old, which means it's time to celebrate her doljabi--the Korean first birthday tradition where a child chooses an object that will determine their future. Each member of the family hopes for Binna to pick a different object. Hoon desperately wants Binna to choose the thread, which is said to guarantee her a long life, but she seems to have other plans. Can he influence her to pick the right item? And what will happen if she chooses a different one instead?