Yunjae was born with a brain condition called Alexithymia that makes it hard for him to feel emotions like fear or anger. He lives with his mother and grandmother above their used bookstore, decorated with colorful post-it notes that remind him when to smile, when to say "thank you," and when to laugh. When a shocking act of random violence shatters his world, it leaves him alone and on his own. Yunjae retreats into silent isolation, until troubled...