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?