Drawings of “I wanted to protect that smile” - Heartrendingly Radiant

Seeing these characters smiling so radiantly really hits you right in the feels, doesn’t it? The tag “I wanted to protect that smile” is used for drawings that feature the smiles of characters who, for a variety of reasons, are no longer able to. 

What smile did you want to protect the most? And what sort of situation hit you the hardest?